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Caenis maduraiensis Balasubramanian and Muthukatturaja, 2021 (Figs. 8–19) Materials examined. Photos of paratype provided by Zoological Survey of India (ZSI), Southern Regional Centre, Chennai, India. 2 L-S-IJ (AMC /ZN/199), 2 L-S-I ♀ (AMC /ZN/200), South India, Tamil Nadu, Madurai District, Vaigai river, 10°08′32′′N, 77°93′20′′E, 192 m; 3.X.2020, colls. P. Srinivasan & R. Isack. Diagnosis. Caenis maduraiensis can be distinguished from all other Indian representatives of Caenis by the following combination of characters, in the imago: 1) base of antennal flagellum not dilated; 2) foremargin between lateral and frontal ocelli slightly bowed (Fig. 9); 3) foretarsus segment 2 with an apico-median projection (Muthukatturaja and Balasubramanian 2021; Fig. 24); 3) penis broad, with rounded lobes of moderate length (Fig. 10); 4) forceps marginally narrowed to the tip, with a short spine bent medially and basally with a small rounded bulging in the outer margin (Fig. 10). Larva: 1) cuticle of femora of all legs light brownish-ochre, with diffuse light and darker areas; tibiae and tarsi light brownish-ochre (Fig. 11); 2) forefemur with a transverse row of 6–7 strongly developed spatulate setae on ¾ of distal region (Fig. 11); 3) proximal inner margin of forefemur with a row of long hair-like bristles (Fig. 11); 4) hindclaw with a row of very fine microdenticles (Fig. 13); 5) hind margin of sternum IX posteriorly protruding and triangular rounded on the apex (Fig. 14). Egg: 1) chorion strongly pored with two epithemata of coiled-rope-type with numerous small terminal knobs, located at the poles (Fig. 18); 2) micropyle short and triangular. Additions to the description. Detailed descriptions of the imago and larva of Caenis maduraiensis are given by Muthukatturaja and Balasubramanian (2021). However, several important diagnostic characters of the imago and larva were not described in the original description. Male imago (Fig. 8). Foremargin between lateral and frontal ocelli slightly bowed (Fig. 9). Forceps marginally narrowed to the tip, with a short spine bent medially and basally with a small rounded bulging in the outer margin (Fig. 10). Larva. Legs. Cuticular coloration: Femora of all legs light brownish-ochre, with diffuse light and darker areas; tibiae and tarsi light brownish-ochre. Foreleg. Femur with a transverse row of 6–7 strongly developed spatulate setae on ¾ of distal region (Fig. 11), row of long hair-like bristles present on 1/3 of the proximal inner margin. Hindleg. Dorsal surface of femur with only a few spatulate setae on the proximal half (Fig. 12). Claw with a row of very fine microdenticles, subequal in size (Fig. 13). Abdomen. Hind margin of sternum IX posteriorly protruding, triangular, rounded on the apex (Fig. 14); shagreen on dorsal side of sternum IX with 6–7 irregular rows of very small denticles parallel to the hind margin (Fig. 15). Egg. Length: 105–110 μm; width: 45–55 μm. Elongated (Fig. 16); chorion strongly pored (Fig. 18) with two epithemata of coiled-rope-type with numerous small terminal knobs, located at the poles (Fig. 18). Epithemata of a modified C. perpusilla subtype (Fig. 17). Micropyle short and triangular. Discussion. Formerly Srinivasan et al. (2021a), misidentified specimens of C. maduraiensis as Caenis nigropunctatula based on the similar kind of genitalia of the male imago. However, C. maduraiensis can be distinguished from C. nigropunctatula by, in imago, i) bowed foremargin between lateral and frontal ocelli, whereas, in C. nigropunctatula, fore margin between lateral and frontal ocelli straight (Malzacher 2015; Fig. 4l); ii) basal part of the forceps with a small rounded bulging in the outer margin, whereas, in C. nigropunctatula, no bulging in the basal part of the forceps (Malzacher 2015; Fig. 1c–i). In larva, i) dorsal surface of forefemur with a transverse row of 6–7 strongly developed spatulate setae on ¾ of distal region, whereas, in C. nigropuctatula, no transverse row in the dorsal surface of forefemur (Malzacher, 2015); ii) foreclaw without any denticulation, whereas, in C. nigropunctatula, foreclaw with a row of strong denticles (Malzacher 2015; 2d); iii) shagreen on dorsal side of sternum IX with 6–7 irregular rows of very small denticles parallel to the hind margin, whereas, in C. nigropunctatula, no shagreen field present on the sternum IX (Malzacher, 2015). Distribution. Vaigai river, Madurai, Tamil Nadu, India. Ecology. Larvae of Caenis maduraiensis were collected in the water temperature ranges between 24°C–26°C; pH 7.2–7.3. Substratum is mainly made of cobbles and pebbles. The larvae of Caenis maduraiensis shared habitat with Choroterpes (Euthraulus) latus (Leptophlebiidae), Tenuibaetis sp. (Baetidae), Labiobaetis operosus (Baetidae), Nigrobaetis klugei (Baetidae), Tricorythus meenakshi (Tricorythidae), Caenis venkataramani sp. n. (Caenidae) and Clypeocaenis kaveri (Caenidae)., Published as part of Srinivasan, Pandiarajan, Sivaruban, T., Barathy, S. & Isack, Rajasekaran, 2023, Contribution to the knowledge of family Caenidae (Insecta: Ephemeroptera) from Madurai District, Tamil Nadu, pp. 39-75 in Zootaxa 5258 (1) on pages 42-44, DOI: 10.11646/zootaxa.5258.1.2, http://zenodo.org/record/7773275, {"references":["Balasubramanian, C. & Muthukatturaja, M. (2021) Two additional new species of Clypeocaenis Soldan, 1978 (Ephemeroptera: Caenidae) from the Western Ghats of Peninsular India. Zootaxa, 4915 (3), 377 - 388. https: // doi. org / 10.11646 / zootaxa. 4915.3.6","Malzacher, P. (2015) Revision of the Oriental species of the genus Caenis Stephens (Insecta: Ephemeroptera: Caenidae). Stuttgarter Beitrage zur Naturkunde A, Neue Serie, 8, 27 - 47."]}

Caenis venkataramani sp. n. (Figs. 58–99) Materials examined. Holotype. L-S-IJ, South India, Tamil Nadu, Madurai District, Vaigai river, 10°08′86′′N, 77°85′28′′E, 204 m, 24.IX.2020, colls. P. Srinivasan & R. Isack (Reg. No. ZSI – SRC /I/E/743). Paratypes. 1 L-S-I ♀ (Reg. No. ZSI – SRC /I/E/744), 2 L-S-IJ, 1 L-S-I ♀, 5 larvae (AMC / ZN /201), South India, Tamil Nadu, Madurai District, Vaigai river, 9°95′52′′N, 78°06′59′′E, 144 m, 13.VI.2021, colls. P. Srinivasan & R. Isack. 2 L-S-IJ, Tamil Nadu, Madurai District, Karuppaurani lake, 9°94′07′′N, 78°18′84′′E, 132 m, 24.V.2020, colls. P. Srinivasan & R. Isack. 1 L-S-I ♀, South India, Tamil Nadu, Madurai District, Vaigai river, 9°95′52 ′′N, 78°06′59′′E, 192 m, 16.VI.2021, colls. P. Srinivasan & R. Isack (AMC /ZN/202). Diagnosis. Caenis venkataramani sp. n. can be distinguished from all other Caenis species by the following combination of characters: Imago: 1) terga I–VI whitish with transverse black tinges (Fig. 60); 2) scutellum pale (Fig. 59); 3) base of antennal flagellum not dilated; 4) prosternal sclerite bell-shaped (Fig. 62); 5) foretarsus segments 2–4 each with a small tongue-shaped apico-median projection (Fig. 64); 6) penis narrow, more or less heart shaped, medio-laterally with short rounded lobes, hind margin with a well-developed medial incision; (Fig. 66) 7) basal half of forceps broad, abruptly narrowed in the apical part, apically with a long spine (Fig. 67). Larva: 1) genae distinctly bulged; 2) mesonotum with margins denticulate with slight bulging (Fig. 79); 3) forefemur with a transverse row of 6–7 strongly developed spatulate setae (Fig. 82); 4) hindclaw strongly bent with 3 very small basal denticles and a row of microdenticles (Fig. 91); 5) tergalius II with Y-shaped ridges poorly developed, inner one posteriorly reduced (Fig. 92); 6) hind margin of sternum IX broadly or triangularly rounded (Fig. 96); 7) shagreen on dorsal side of sternum IX with 8–9 irregular rows of very small denticles parallel to the hind margin. Egg: 1) two cap-like epithemata at the poles (Fig. 97); 2) chorionic surface smooth with transverse slender micropylar canal between polar caps (Fig. 98); 3) micropyle small with mouth not broadened (Fig. 99). Description. Male imago (Fig. 58). Measurements. Body length: 3.3 mm; forewing length: 2.1 mm; foreleg length: 2.1 mm; midleg length: 1.1 mm; hindleg length: 1.3 mm; cercus length: 7.8 mm. Ratios. Head (see Malzacher 2015; Fig. 4k): c: a = 2.3, a: b = 1; Leg: fore femur: fore tibia = 0.61; fore tibia: fore tarsus = 1.66; fore leg: hind leg = 1.6; segments of fore tarsus 1st: 2nd: 3rd: 4th: 5th = 1: 4.5: 3.1: 2.7: 1.4 Coloration. Head: Vertex with a dark brownish transverse band between lateral ocelli. Antenna: scape and pedicel pale. Thorax (Fig. 59): Pronotum with two black spots submedially and dark stripes laterally. Mesonotum dark brownish with stripes in the lateral areas; scutellum pale; mesonotal suture darkly pigmented; prosternum light brownish with dark stripes laterally, mesosternum, and metasternum light brownish, laterally with dark stripes. Wings hyaline, costa and subcostal veins reddish-brown. Legs whitish, except apical part of femora with a dark brownish patch; tibia dark brownish. Abdomen (Fig. 60): General coloration of terga whitish; terga I–VI whitish with transverse black tinges; terga VII–IX whitish with darkened lateral areas. Cerci translucent. Head (Fig. 61). Fore margin between lateral and frontal ocelli straight. Pedicel two times the length of scape. Base of the antennal flagellum not dilated. Thorax. Prosternal sclerites strong, forming an apically blunt or protruded isosceles triangle, without transverse strip (Figs. 62, 63). Foretarsus segments 2–4 each with a small tongue-shaped apico-median projection (Fig. 64) equipped with strong small spines (Fig. 65). Abdomen. Tergum II without a finger-like process. Lateral filaments short. Genitalia and sternum IX as in Fig. 66. Penis narrow, more or less heart shaped, medio-laterally with short rounded lobes, hind margin with a well-developed medial incision (Fig. 67); styliger sclerite with very short apophyses. Basal half of forceps broad, abruptly narrowed in the apical part, apically with a long spine (Fig. 67). Female imago (Fig. 68). Measurements. Body length: 5.3 mm; forewing length: 2.8 mm. Coloration is similar to that of males. Terga I–VI transverse band strongly pronounced compared to that of males. Mature larva (Fig. 69). Measurements. Body length (Fig. 13): 4.9–5.1 mm in female; 3.3–3.5 mm in male. Cerci length: 3.2–3.3 mm in female; 1.5–1.6 mm in male. Antennae length: 1.5–1.7 mm. Head. Length 0.54 mm, width 0.82 mm. General coloration brown, vertex with a dark brownish transverse band between lateral ocelli. Hind margin without setae, antenna with fine, thin setae on each articulation. Pedicel two times the length of scape and with 3–4 simple setae on lateral margins (Fig. 71), genae distinctly bulged in lateral view. Mouthparts: Labrum (Fig. 72) twice as broad as long, medial emargination with thick setae, lateral margin with long simple setae, dorsal and ventral surface with scattered long, fine simple setae. Hypopharynx (Fig. 73) with minute hair-like setae on the apical margin and superlingua with long simple setae on the lateral margins. Right mandible. Outer incisor with three denticles and inner incisor with two denticles; medial margin with a small process between mola and incisors (Fig. 74). Left mandible. Outer incisor with five denticles; inner incisor with three denticles; medial margin without any process between mola and incisors (Fig. 75). The dorsal surface and outer margin of both mandibles scattered with a row of long, simple setae. Maxilla (Fig. 76). Three-segmented maxillary palp and with a ratio of 1: 0.6: 1; segment I with a row of five curved, spine-like setae on the outer margin; segment III with a longitudinal row of long simple setae near the inner marginal surface. Labium (Fig. 77). Glossa and paraglossa scattered with long, spine-like setae; three-segmented labial palp with length ratio of 1: 0.8: 0.6 (Fig. 77); segment I with a row of ten bipinnate bristles in the outer margin, segment II with long hair-like setae with 7–8 pectinate setae in the outer margin; surface with a bipinnate seta (Fig. 79), segment III with 6–8 spine-like setae in the inner margin and two transverse rows of long, spine-like setae on the apex along with scattered long hair-like setae on the surface and outer margin. Thorax. Pronotum and mesonotum dark brownish and epidermal pigmentation similar to that of imago. Mesonotum with margins denticulate with slight bulging (Fig. 78). Legs: Cuticular coloration: Femora, tibiae and tarsi light brownish. Coxal processes nearly semi-circular with denticulate margins. Foreleg (Fig. 81): lengths of femur: tibia: tarsus: claw 0.55: 0.44: 0.32: 0.15 mm; femur with a transverse row of 6–7 strongly developed spatulate setae (Fig. 83) on ¾ of the distal region (Fig. 82); near the outer marginal surface a longitudinal row of spatulate setae present; distal outer margin consists of few spatulate setae; inner margin with row of long hair-like setae on the proximal half; tibia with longitudinal row of 4–5 spatulate setae on dorsal surface; outer margin with few hair-like setae; tarsi with longitudinal row of seven bipinnate bristles; outer and inner margins with few hair-like setae; claw slender without any denticulation (Fig. 80). Midleg (Fig. 84): lengths of femur: tibia: tarsus: claw 0.57: 0.36: 0.29: 0.15 mm. Femur with scattered spatulate bristles all over the surface; outer margin consists of a row of long spatulate setae; tibia with longitudinal row of 6–7 spatulate setae on dorsal surface; outer margin with row of short spine-like setae; tarsi with a longitudinal row of seven stout, bipinnate bristles, increasing in size distally; claw (Fig. 85) long, and curved without any denticles. Hindleg: lengths of femur: tibia: tarsus: claw 0.59: 0.47: 0.32: 0.15 mm. Femur (Fig. 86) similar to that of midleg; tibia (Fig. 87) with longitudinal row of 6–7 spatulate setae on dorsal surface (Fig. 88); outer margin with row of long spine-like setae; tarsi with a longitudinal row of seven stout, bipinnate bristles, increasing in size distally near the inner margin and a longitudinal row of spine-like setae on the inner margin (Fig. 89); claw strongly bent with three very small basal denticles (Fig. 91), and a row of microdenticles (Fig. 90). Abdomen. All terga nearly light brownish. Tergalius II with diffuse light and dark brown areas without any shading medially and with dark brown patches on the other regions (Fig. 92). Tergalius II about twice the length of tergalius I. Tergum I lack posteromedian process; tergum II with a broadly blunt triangular posteromedian process with denticulate hind margin; Tergalius II with Y-shaped ridges poorly developed, inner ridge posteriorly reduced (Fig. 92); dorsal surface with numerous scales and 3–4 spatulate setae on the 1/3 rd half of Y-shaped ridge; left margin of Y-shaped ridge with a row of long simple setae with few small spatulate setae. Right margin of Y-shaped ridge with a row of small simple setae. Ventral row of microtrichia originates at anterior 1/5 th length of the tergalius II and ends in the posteromedial region; microtrichia elongated, more or less parallel-sided, and pinnate (Fig. 93). Tergalius III–VI with numerous filaments (Fig. 94). Posterolateral processes on tergum I absent; terga II–III with slightly marked posterolateral processes; terga IV–IX with well-developed posterolateral processes. Hind margins of tergum VII with long hair-like setae and tergum VIII with few long hair-like setae (Fig. 95) and terga IX and X with small denticles. Hind margin of sternum IX broadly or triangularly rounded (Fig. 96), shagreen on dorsal side of sternum IX with 8–9 irregular rows of very small denticles parallel to the hind margin. Cerci translucent. Egg. Length: 110–115 μm; width: 70–75 μm; oval (Fig. 97); two cap-like epithema at the poles (Fig. 97); chorionic surface smooth with transverse slender micropylar canal between polar caps (Fig. 98), micropyle small, situated at the subequatorial plane with mouth not broadened (Fig. 99). Etymology. This new species is named in honour of Dr. K. Venkataraman (mentor for the authors T. Sivaruban and S. Barathy) for his remarkable contribution to the Indian Ephemeroptera. Distribution. Vaigai river, Madurai, Tamil Nadu, India. Ecology. Larvae of Caenis venkataramani sp. n. were collected in the water temperature ranges between 24°C– 26°C; pH 7.2–7.3. Substratum is mainly made of cobbles and pebbles. The larvae of the Caenis venkataramani sp. n. shared their habitat with the larvae of Choroterpes (Euthraulus) latus (Leptophlebiidae), Tenuibaetis sp. (Baetidae), Labiobaetis operosus (Baetidae), Nigrobaetis klugei (Baetidae), Cheleocloeon vaigaiensis (Baetidae), Tricorythus meenakshi (Tricorythidae), Caenis maduraiensis (Caenidae) and Clypeocaenis kaveri (Caenidae). Discussion. The male imago of Caenis venkataramani sp. n. is distinguished from other Oriental species of Caenis, except C. maratha by the shape of forceps, in which the basal part is very broad and the apical part is abruptly narrowed. It is distinguished from C. maratha by a well-developed medial incision in the hind margin of the penis. The larva of Caenis venkataramani sp. n. closely resembles that C. maduraienis and C. nigropunctatula. However, it is distinguished from C. maduraienis and C. nigropunctatula by the denticulation of the hind claw and by the mesonotal bulging in the larva and by the shape of the forceps in the imago.

Caenis arunachalami sp. n. (Figs. 100–142) Materials examined. Holotype. L-S-IJ, South India, Tamil Nadu, Madurai District, Nagamalai, Pulluthu stream, 9°95′30′′N, 78°03′92′′E, 212 m, 13.X.2020, colls. P. Srinivasan & R. Isack (Reg. No. ZSI –SRC/I/E/740). Paratypes. 2 L-SJ, 2 L-S-I ♀ (AMC /ZN/255), 7 larvae (AMC /ZN/256), 1 larva (Reg. No. ZSI –SRC/I/E/741) with same label data as holotype. Diagnosis. C.arunachalami sp. n. can be distinguished from all other Caenis species by the following combination of characters: Imago: 1) dark brownish body coloration and terga III–VII and X with a darker longitudinal line medially (Fig. 100); 2) base of antennal flagellum well dilated (Fig. 101); 3) prosternal sclerites forming an open triangle with concave sides (Fig. 103); 4) foretarsus segments 2–4 each with an apico-median projection (Fig. 102); 5) contrasting coloration of forceps and penis (Fig. 104); 6) penis narrow without any bulging lobes; posterior margin nearly straight without any medial emargination (Fig. 105); 7) forceps short, subcylindrical, broad, apically with a long hook-like spine equipped with 2–3 small spines near the apex (Fig. 106). Larva: 1) genae distinctly bulged (Fig. 109); 2) femur of each leg ochre with contrasting dark brownish patch in the 3/4 th distal apex; tibia and tarsus of each leg ochre with dark brownish band at middle (Fig. 129); 3) mesonotum with margins denticulate; 4) forefemur with a transverse row of 6–7 strongly developed spatulate setae on ¾ of distal region (Fig. 122); 5) hindclaw long and slightly curved, with a row of very fine microdenticles, medial denticles larger compared to basal denticles (Fig. 131); 6) tergalius II with left margin of Y-shaped ridge bearing row of long simple setae in the proximal half and row of spatulate setae in the distal half (Fig. 132); 7) hind margin of sternum IX posteriorly protruding and blunt triangular with a rounded tip on the apex (Fig. 137). Egg: 1) chorion smooth with a flat epithema of coiled-rope type located at the pole (Figs. 140, 141); 2) micropyle with broadened mouth (Fig. 142). Description. Male imago (Fig. 100). Measurements. Body length: 2.5 mm; forewing length: 2.2 mm; foreleg length: 2.1 mm; midleg length: 1 mm; hindleg length: 1.2 mm; cercus length: 7.7 mm. Ratios. Head (see Malzacher 2015; Fig. 4k): c: a = 2.2, a: b = 1.3; Leg: fore femur: fore tibia = 0.58; fore tibia: fore tarsus = 1.27; fore leg: hind leg = 1.75; segments of fore tarsus 1st: 2nd: 3rd: 4th: 5th = 1: 3.1: 2.8: 2.3: 1.9 Coloration. Head: Vertex with intense blackish transverse band. Antenna: scape and pedicel light brownish, flagellum whitish shaded with gray at base. Thorax: Prothorax light brownish medially and dark brownish laterally; prosternum medially dark brownish and laterally yellowish brown. Mesonotum and metanotum dark brown; mesosternum and metasternum dark brownish. Wings hyaline, costa, and subcostal vein reddish-brown. Legs whitish, except apical part of femora and tibiae with a dark brownish patch. Abdomen: Terga I–II dark brownish, terga III–VIII with transverse light brownish tint medially and paler laterally and tergum IX & X darker; terga III– VII & X with a darker longitudinal line medially, in tergum VIII & IX, medial longitudinal line poorly expressed. Cerci translucent. Head (Fig. 101). Foremargin between lateral and frontal ocelli convex. Pedicel twice the length of scape; pedicel well dilated laterally. Base of the antennal flagellum well dilated. Thorax. Prosternal sclerites narrow, forming an open triangle with concave sides; transverse strip long, present just above the opening,prosternal triangle entirely washed with dark brownish pigmentation(Fig.103).Foretarsus segments 2–4 apically with a small tongue-shaped apico-median projection, equipped with small strong spines (Fig. 102). Abdomen. Tergum II without a finger-like process. Lateral filaments short. Genitalia and sternum IX as in Fig. 104. Penis short, broad, without any bulging lobes, nearly in the posterior margin of styliger sclerite (Fig. 105). Styliger sclerite with apophyses of moderate length (Fig. 106). Forceps short, subcylindrical, broad, apically with a long hook-like spine equipped with 2–3 small spines near the apex (Fig. 106). Genitalia entirely washed with brownish pigmentation and with very minute hairs; penis and forceps translucent; styliger sclerite dark brownish; central sclerite light brownish. Female imago (Fig. 107). Measurements. Body length: 3.8 mm; forewing length: 2.6 mm. Coloration is similar to that of males. Terga III–VIII brownish tint strongly pronounced compared to that of males. Mature larva (Fig. 108). Measurements. Body length: 3.3–3.5 mm in female; 2.4–2.5 mm in male. Cerci length: 3 mm in female; 1.3 mm in male. Antennae length: 0.7–0.8 mm. General body coloration is usually dark brown dorsally and pale brown ventrally. Head. Length 0.37 mm, width 0.59 mm. General coloration dark brown, with dark blackish transverse band between lateral ocelli; vertex dark brown without any markings (Fig. 109). Hind margin without setae, antenna with fine, thin setae on each articulation at every 3 rd segment. Pedicel twice the length of scape and with 1–2 simple setae on lateral margins, genae distinctly bulged (Fig. 109). Mouthparts: Labrum (Fig. 110) twice as broad as long, medial emargination with thick setae, lateral margin with long simple setae, dorsal and ventral surface with scattered long, fine simple setae (Fig. 111). Hypopharynx (Fig. 112) with minute hair-like setae on the apical margin and emarginate, superlingua with long simple setae on the lateral margins (Fig. 113). Right mandible (Fig. 114). Outer incisor with three denticles in which the outermost denticle possesses 4–5 long, fine setae; inner incisor with two denticles; medial margin with a small process between mola and incisors. Left mandible (Fig. 115). Outer incisor with four denticles; inner incisor with three denticles; medial margin without any process between mola and incisors. Dorsal surface of both mandibles scattered with scales and row of long setae laterally and a few long setae near the surface of the outer margin. Maxilla (Fig. 116). Three-segmented maxillary palp and with ratio of 1: 0.60: 0.94; segment I with row of 4–6 spines on outer margin; segment III with longitudinal row of long setae near inner marginal surface. Labium (Fig. 117). Glossa with five small spines laterally; paraglossa with scattered long simple setae (Fig. 118); three-segmented labial palp with length ratio of 1: 0.81: 0.50; segment I with row of bipinnate setae in the outer margin (Fig. 119), segment II with scattered long hair-like setae all over the surface and in the outer margin; outer marginal surface with a row of 9–10 bipinnate setae, segment III with seven spine-like setae in the inner margin and two transverse rows of four spine-like setae on the apex. Thorax. Pronotum dark brown medially with traphezoidal marking medially; mesonotum dark brown. Margins of mesonotum denticulate with slight bulging. Legs: Cuticular coloration (Fig. 120, 126, 129): Femur of each leg ochre with contrasting dark brownish patch in the 3/4 the distal apex; tibia and tarsus of each leg ochre with dark brownish band at middle. Hypodermal coloration: Coloration of legs coinciding with cuticular coloration. Coxal processes semicircular with denticulate margins. Trochanter with four small spine-like setae on the inner margin and 4–5 spatulate setae near the surface of the outer margin. Foreleg (Fig. 120): lengths of femur: tibia: tarsus: claw 0.30: 0.22: 0.17: 0.08 mm; femur (Fig. 121) with a transverse row of 6–7 strongly developed spatulate setae on ¾ of distal region (Fig. 122); distal outer margin consists of 4–5 slightly developed spatulate setae; femora covered with numerous scale bases; tibia with longitudinal row of strongly developed spatulate setae on dorsal surface (Fig. 123), cluster of a large pectinate seta, three bipectinate setae and two long strongly developed spatulate setae present on its distal region; tarsi with longitudinal row of spine-like setae, increasing in size towards the distal half (Fig. 124); proximal inner marginal surface bears two bipectinate setae; claw long, curved and pointed with 4–6 minute denticles, which are of different in size (Fig. 125). Midleg (Fig. 126): lengths of femur: tibia: tarsus: claw 0.28: 0.22: 0.18: 0.08 mm. Femur with scattered strongly developed spatulate setae all over the surface; distal outer margin consists of 4–5 slightly developed spatulate setae; tibia bears a longitudinal row of seven strongly developed spatulate setae on its surface; distal region of tibia with a large apically blunt bipinnate seta; tarsi with longitudinal row of bipinnate setae, increasing in size distally (Fig. 127); midclaw (Fig. 128) bears seven denticles (four on dorsal side and three on ventral side). Hindleg (Fig. 129): lengths of femur: tibia: tarsus: claw 0.30: 0.25: 0.20: 0.09 mm. Femur with strongly developed spatulate setae all over the surface; outer margin (both proximal and distal margin) with slightly developed spatulate setae; tibia same as of midleg; tarsi with two longitudinal rows of pectinate and bipinnate setae (Fig. 130); claw long and slightly curved, 2 basal denticles, and with a row of very fine microdenticles, medial denticles larger compared to basal one (Fig. 131). Abdomen. Terga I, VIII, and IX dark brown; tergum X light brown; others whitish and laterally translucent. Tergum I lack posteromedian process; tergum II with a broadly blunt triangular posteromedian process and denticulate hind margin; posterolateral processes on terga I–II absent; tergum III with slightly marked posterolateral processes; terga IV–VII with well-developed posterolateral spines processes (Fig. 136); terga VIII–IX posterolateral spines subequal in size. Hind margins of terga VII and VIII with bristles and terga IX and X with small denticles. Tergalius II about twice the length of tergalius I. Tergalius II with complete and well-developed Y-shaped ridge (Fig. 132); dorsal surface with numerous scales and 4 spatulate setae on the 2/3 rd half of Y-shaped ridge (Fig. 133). Left margin of Y-shaped ridge with row of long simple setae in the proximal half and row of spatulate setae in the distal half margin. Right margin of Y-shaped ridge with row of long simple setae. Ventral row of microtrichia originates at anterior 1/5 th length of the tergalius II; microtrichia more elongated and pinnate (Fig. 134). Tergalius III–VI with numerous filaments (Fig. 135). Hind margin of sternum IX posteriorly protruding and triangular rounded on the apex (Fig. 137); shagreen on dorsal side of sternum IX with 4–5 irregular rows of very small denticles parallel to the hind margin (Fig. 138). Cerci translucent. Egg. Length: 105–115 μm; width: 70–80 μm. Oval (Fig. 139); chorion smooth with a flat epithema of coiledrope type located at the pole (Figs. 140, 141); micropyle situated at the subequatorial plane and slightly bent with broadened mouth (Fig. 142). Etymology. This species is named in honour of Dr. M. Arunachalam (Central University of Kerala, School of Biological Sciences, Department of Animal Science/Zoology, Periye, India) who is the mentor and guide for the authors T. Sivaruban and S. Barathy, for his outstanding contribution to the benthic macroinvertebrates. Distribution. Nagamalai hills, Madurai, Tamil Nadu, India (Southern Eastern Ghats). Ecology. Larvae of Caenis arunachalami sp. n. were collected in a freshwater stream of 10 m wide with 80% canopy cover. The water temperature ranges between 22°C–24°C; pH 7.1–7.3. Substratum is mainly made of cobbles, pebbles, leaf litter with silt and organic matter. The larvae of the Caenis arunachalami sp. n. shared their habitat with the larvae of Labiobaetis sp. (Baetidae). Discussion. The male imago of Caenis arunachalami sp. n. is distinguished from other Oriental species of Caenis by the unique coloration of the body and genitalia. The coloration of the adult closely resembles that of the Ethiopian species C. gretathunbergae Malzacher 2021 (Malzacher 2021, Fig. 15), however, the new species can be distinguished from C. gretathunbergae, by the shape of forceps and penis in the male imago and by the shape of sternum IX in the larva (Malzacher 2021).

Caenis kaegies sp. n. (Figs. 20–57) Materials examined. Holotype. L-S-IJ, South India, Tamil Nadu, Madurai District, Vaigai river, 9°95′52′′N, 78°06′59′′E, 192 m, 16.VI.2021, colls. P. Srinivasan & R. Isack (AMC /ZN/253). Paratypes. 1 L-SJ, 2 L-S-I ♀, 2 larvae (AMC /ZN/254), 1 larva (Reg. No. ZSI –SRC/I/E/742) with same label data as holotype. Diagnosis. Caenis kaegies sp. n. can be distinguished from all other Caenis species by the following combination of characters: Imago: 1) terga I–VI with more or less intense blackish transverse bands (Fig. 22); 2) scutellum darkly pigmented with anvil-shaped marking (Fig. 28); 3) base of antennal flagellum not dilated (Fig. 23); 4) prosternal sclerites bell-shaped (Fig. 24); 5) foretarsus segments 2–4 each with a small tongue-shaped apico-median projection (Fig. 25); 6) penis broad, with short rounded lobes (Fig. 26); 7) forceps short, basally broadened, consisting of a strong spine with blunt apex equipped with apical tuft of long spines (Fig. 27). Larva: 1) genae distinctly bulged; 2) pronotum and mesonotum denticulate without any bulging margins; 3) forefemur with a transverse row of 7–8 strongly developed spatulate setae (Fig. 39); 4) hindclaw with 3–4 basal denticles increasing in size distally, and a row of microdenticles, decreasing in size towards the distal end (Fig. 47); 6) dorsal surface of tergalius II with numerous scales and 4–5 spatulate setae on the 2/3 rd half of Y-shaped ridge (Fig. 49); 7) hind margin of sternum IX rounded with numerous minute indentations medially (Fig. 52). Egg: 1) chorion finely pored with a cap-like epithema (Fig. 55); 2) micropyle with mouth not broadened (Fig. 56). Description. Male imago (Fig. 20). Measurements. Body length: 1.8 mm; forewing length: 1.3 mm; foreleg length: 1.7 mm; midleg length: 0.7 mm; hindleg length: 0.8 mm; cercus length: 4.8 mm. Ratios. Head (see Malzacher 2015; Fig. 4k): c: a = 2.3, a: b = 1.1; Leg: fore femur: fore tibia = 0.51; fore tibia: fore tarsus = 1.42; fore leg: hind leg = 2.10; segments of fore tarsus 1st: 2nd: 3rd: 4th: 5th = 1: 4.6: 2.4: 1.9: 1. Coloration. Head:Vertex with two more or less intense dark brownish transverse bands (Fig. 23).Antenna: scape and pedicel pale. Thorax: Prothorax dark brownish stripes medially and laterally, posterior margin of pronotum with dark brownish transverse band. Mesonotum generally pale with two black longitudinal bands in the sub medial area; scutellum darkly pigmented with anvil-shaped marking (Fig. 21); mesonotal suture darkly pigmented; prosternum, mesosternum, and metasternum pale yellowish. Wings hyaline, costa, and subcostal veins reddish-brown. Legs whitish, except apical part of femora and tibiae with a dark brownish patch. Abdomen: Terga I–VI with more or less intense blackish transverse bands, terga VII–IX (Fig. 22) mostly colourless medially and laterally with intense blackish stripes, tergum X mostly colourless. Cerci translucent. Head (Fig. 23). Fore margin between lateral and frontal ocelli slightly bowed. Pedicel 2.5 times the length of scape. Base of the antennal flagellum not dilated. Thorax. Prosternal sclerites forming a bell-shape; base of the triangle washed with dark brownish pigmentation (Fig. 24). Foretarsus segments 2–4 with a small tongue-shaped apico-median projection (Fig. 25) equipped with strong small spines. Abdomen. Tergum II without a finger-like process. Lateral filaments short. Genitalia and sternum IX as in Fig. 26. Penis broad, with short rounded lobes, hind margin with a well-developed medial incision. Styliger sclerite broad with very short apophyses. Forceps longer than penis lobe, basally broadened, consisting of a strong spine with blunt apex equipped with apical tuft of long spines (Fig. 27). Female imago (Fig. 28). Measurements. Body length: 3.8 mm; forewing length: 2.6 mm. Coloration similar to that of males. Terga I–VI with blackish transverse band strongly pronounced compared to that of males. Mature larva (Fig. 29). Measurements. Body length: 3.4–3.5 mm in female; 2.5–2.7 mm in male. Cerci length: 1.7–2 mm in female; 1.2–1.4 mm in male. Antennae length: 0.8–1 mm. Head. Length 0.40 mm, width 0.67 mm. General coloration brown, with a dark brownish transverse band between lateral ocelli; vertex dark brown with branch-like markings (Fig. 29). Hind margin without setae, antenna with thin setae on each articulation. Pedicel 1.5 times longer than scape and with 3–4 simple setae on lateral margins, genae distinctly bulged in lateral view. Mouthparts: Labrum (Fig. 31) twice as broad as long, medial emargination with thick setae, lateral margin with long simple setae, dorsal and ventral surface with scattered long, fine simple setae. Hypopharynx with minute hair-like setae on the apical margin and superlingua with long simple setae on the lateral margins. Left mandible. Outer incisor with four denticles; inner incisor with two denticles; medial margin without any process between mola and incisors (Fig. 32). Right mandible. Both outer and inner incisors with two denticles; medial margin with a small process between mola and incisors (Fig. 33). Dorsal surface and outer margin of both mandibles scattered with a row of long, strongly spatulate setae (Fig. 34). Maxilla (Fig. 35). Threesegmented maxillary palp; length ratio of palp segments 1: 0.6: 0.9; segment I with a row of five bipinnate bristles on the outer margin (Fig. 36); segment III with a longitudinal row of long simple setae the inner margin. Labium. Glossa with few small spines laterally; paraglossa with scattered long, spine-like setae (Fig. 37); three-segmented labial palp with length ratio of 1: 0.9: 0.5 (Fig. 37); segment I with a row of seven bipinnate bristles in the outer margin, segment II with long hair-like setae all over the surface and in the outer margin; outer marginal surface with a row of 5–7 pectinate setae, segment III with 6–8 spine-like setae on the inner margin and two transverse rows of long, spine-like setae on the apex along with scattered long hair-like setae on the surface and outer margin. Thorax. Pronotum and mesonotum dark brownish; epidermal pigmentation similar to that of imago (Fig. 30). Mesonotum with denticulate margins without any bulging. Legs. Cuticular coloration: Femora light brownish with diffuse light and dark areas; tibiae and tarsi light brownish. Coxal processes nearly semi-circular with denticulate margins. Foreleg (Fig. 38): lengths of femur: tibia: tarsus: claw 0.38: 0.28: 0.23: 0.14 mm; femur with a transverse row of 7–8 strongly developed spatulate setae on ¾ of the distal region (Fig. 39); proximal outer margin consists of few spatulate setae; inner margin with row of long hair-like setae on the proximal half; tibia with longitudinal row of 5–6 spatulate setae on dorsal surface; outer margin with few hair-like setae (Fig. 40); tarsi with longitudinal row of two bipinnate bristles on the distal end; outer and inner margins with few hair-like setae; claw slender with four minute basal denticles (Fig. 41). Midleg (Fig. 42): lengths of femur: tibia: tarsus: claw 0.36: 0.22: 0.21: 0.15 mm. Femur with scattered spatulate bristles all over the surface; outer margin consists of a row of long spatulate setae; tibia with longitudinal row of 5–6 spatulate setae on dorsal surface (Fig. 43); outer margin with row of short spine-like setae; tarsi with a longitudinal row of six stout, bipinnate bristles of variable in size; claw (Fig. 44) long, broad, and curved with six basal denticles. Hindleg (Fig. 45): lengths of femur: tibia: tarsus: claw 0. 40: 0.31: 0.19: 0.15 mm. Femur similar to that of midleg; tibia with longitudinal row of 5–6 spatulate setae on dorsal surface; outer margin with row of long spine-like setae; tarsi similar to that of midleg (Fig. 46); claw strongly curved with 3–4 basal denticles increasing in size distally, and a row of microdenticles, decreasing in size towards the distal end (Fig. 47). Abdomen. Terga I, VII, and VIII dark brown; terga IX and X light brown; others whitish and laterally translucent. Tergalius II with diffuse light and dark brown areas without any shading medially and remaining areas with dark brown patches (Fig. 49). Tergalius II about twice the length of tergalius I. Tergum I without posteromedian process; tergum II with a broadly blunt triangular posteromedian process and denticulate hind margin (Fig. 48); tergalius II with Y-shaped ridges poorly developed, inner ridge posteriorly reduced (Fig. 49); dorsal surface with numerous scales and 4–5 spatulate setae on the anterior 2/3 rd half of Y-shaped ridge (Fig. 49); left margin of Y-shaped ridge with a row of long simple setae with few short spatulate setae. Right margin of Y-shaped ridge with a row of small simple setae. Ventral row of microtrichia originates at anterior 1/5 th length of the tergalius II and ends in the posteromedial region; microtrichia elongated, more or less parallel-sided, and pinnate (Fig. 50). Tergalius III–VI with numerous filaments (Fig. 51). Posterolateral processes on tergum I absent; terga II–III with slightly marked posterolateral processes; terga IV–IX with well-developed posterolateral processes. Hind margins of tergum VII with long hair-like setae and tergum VIII with long hair-like setae along with few spatulate setae and terga IX and X with small denticles. Hind margin of sternum IX rounded with numerous minute indentations medially (Fig. 52), shagreen on dorsal side of sternum IX with 8–9 irregular rows of very small denticles parallel to the hind margin (Fig. 53). Cerci translucent. Egg. Length: 115–125 μm; width: 40–50 μm. Elongated (Fig. 54); chorion finely pored with a cap-like epithema (Fig. 55); micropyle small, situated at the subequatorial plane with mouth not broadened (Fig. 56), with visible circular sperm guide (Fig. 57). Etymology. This species is named in honour of Dr. K.G. Sivaramakrishnan who is the mentor of the authors T. Sivaruban and S. Barathy, who has significantly contributed to the Indian Ephemeroptera. The species “ kaegies ” is an abbreviated patronym of Dr. K.G. Sivaramakrishnan, popularly known as “KGS” and hence the species name. Distribution. Vaigai river, Madurai, Tamil Nadu, India. Ecology. Larvae of Caenis kaegies sp. n. were collected in the riverine ecosystem with high amount of organic pollution, in which temperature ranges between 25°C–27°C; pH 7.3–7.4. Substratum is mainly made of cobbles and silt. The larvae of the Caenis kaegies sp. n. shared their ecological niche with the larvae of Cloeon sp. (Baetidae) and Caenis venkataramani sp. n. (Caenidae). Discussion. Caenis kaegies sp. n. is distinguished from other Oriental species of Caenis by the darkly pigmented scutellum and bell-shaped prosternal triangle in imago. The larva of Caenis kaegies sp. n. closely resembles that of another Indian species, C. limai. However, it is distinguished from C. limai by the absence of bulging in the mesothorax and reduced number of spatulate setae in the transverse row of the forefemur., Published as part of Srinivasan, Pandiarajan, Sivaruban, T., Barathy, S. & Isack, Rajasekaran, 2023, Contribution to the knowledge of family Caenidae (Insecta: Ephemeroptera) from Madurai District, Tamil Nadu, pp. 39-75 in Zootaxa 5258 (1) on pages 44-52, DOI: 10.11646/zootaxa.5258.1.2, http://zenodo.org/record/7773275, {"references":["Malzacher, P. (2015) Revision of the Oriental species of the genus Caenis Stephens (Insecta: Ephemeroptera: Caenidae). Stuttgarter Beitrage zur Naturkunde A, Neue Serie, 8, 27 - 47."]}

Caenis sp. 2 (Figs. 152–156) Materials examined. 5♀ imagoes, South India, Tamil Nadu, Madurai District, Karuppaurani lake, 9°94′07′′N, 78°18′84′′E, 132 m, 24.V.2020, colls. P. Srinivasan & R. Isack (AMC /ZN/266). Description. Female imago (Fig. 152). Measurements. Body length: 2.7 mm; forewing length: 2.5 mm; foreleg length: 1.2 mm; midleg length: 1.2 mm; hindleg length: 1.1 mm; cercus length: 1.4 mm. Coloration. Head: Vertex with dark brownish transverse markings between lateral ocelli. Antenna: scape and pedicel light brownish. Thorax: Prothorax darkened laterally. Mesonotum generally light brownish with two longitudinal bands in the sub medial area; scutellum pale; mesonotal suture darkly pigmented; prosternum, mesosternum, and metasternum pale yellowish. Wings hyaline, costa, and subcostal vein reddish-brown. Legs whitish, except apical part of femora and tibiae with a dark brownish patch. Abdomen: Terga I–IV with a welldeveloped black transverse band, terga IX–X mostly colourless. Cerci translucent. Head. Fore margin between lateral and frontal ocelli slightly bowed. Pedicel two times the length of scape. Base of the antennal flagellum slightly dilated. Thorax. Prosternal sclerites anteriorly converging, forming a broadly rounded triangle; transverse strip short. Abdomen. Tergum II without a finger-like process. Lateral filaments short. Male imago and larva. Unknown. Egg. Length: 110–120 μm; width: 75–85 μm. Oval-shaped (Figs. 153); chorion smooth with an epithemata of coiled-rope-type with numerous small terminal knobs on the pole (Figs. 154, 155). Epithemata of a modified C. perpusilla subtype. Micropyle moderate, situated at the subequatorial plane with mouth not broadened, with well visible circular sperm guide (Fig. 156). Distribution. Karuppaurani lake, Madurai, Tamil Nadu, India. Discussion. The unnamed species Caenis sp. 2 is similar to C. ulmeriana by the egg structure, however, it is distinguished by the smooth chorionic surface (Malzacher and Sangpradub 2020)., Published as part of Srinivasan, Pandiarajan, Sivaruban, T., Barathy, S. & Isack, Rajasekaran, 2023, Contribution to the knowledge of family Caenidae (Insecta: Ephemeroptera) from Madurai District, Tamil Nadu, pp. 39-75 in Zootaxa 5258 (1) on pages 69-70, DOI: 10.11646/zootaxa.5258.1.2, http://zenodo.org/record/7773275

Key to the known males of Caenis Stephens, 1835 from South India (Male adult characters of Caenis sp. 2 is unknown) 1 Base of the antennal flagellum well dilated (Fig. 101)...................................... C. arunachalami sp. n. - Base of the antennal flagellum slightly or not dilated (Fig. 23).................................................. 2 2 Forceps apically with few tuft of short spines (Srinivasan et al. 2023; Fig. 46)........................... C. americani - Forceps apically with a rigid spine (Figs. 27, 67, 106, 147).................................................... 3 3 Foretarsus segments 2–3 each with a lateral and a median projections and segment 4 with an apico-median projection (Fig. 146)....................................................................................... Caenis sp. 1 - Foretarsus segments 2–4 each with an apico-median projection................................................. 4 4 Prosternal sclerite bell-shaped (Fig. 24)....................................................... C. kaegies sp. n. - Prosternal sclerite differently shaped (Figs. 62, 103).......................................................... 5 5 Forceps apically with a short spine (Fig. 10).................................................... C. maduraiensis - Forceps apically with a long spine (Fig. 66)................................................................ 6 6 Hind margin of penis with a well-developed medial incision (Fig. 67)......................... C. venkataramani sp. n. - Hind margin of penis with slight or no medial incision (Srinivasan et al. 2023; Fig. 10)............................. 6 7 Forceps more or less parallel-sided (Srinivasan et al. 2023; Fig. 11)........................................ C. limai - Basal half of forceps very broad, apical part abruptly narrowed (Malzacher 2015; Fig. 5b)................... C. maratha, Published as part of Srinivasan, Pandiarajan, Sivaruban, T., Barathy, S. & Isack, Rajasekaran, 2023, Contribution to the knowledge of family Caenidae (Insecta: Ephemeroptera) from Madurai District, Tamil Nadu, pp. 39-75 in Zootaxa 5258 (1) on page 73, DOI: 10.11646/zootaxa.5258.1.2, http://zenodo.org/record/7773275, {"references":["Stephens, J. F. (1835) Family III. - Ephemeridae, Leach. Illustrations of British Entomology, Mandibulata, 6, 54 - 70.","Srinivasan, P., Sivaruban, T., Barathy, S. & Isack R. (2023) A new species of Caenis Stephens, 1835 and description of male subimaginal characters of Caenis americani Srinivasan et al. 2021 (Ephemeroptera: Caenidae) from the Western Ghats, South India. Aquatic Insects. [in press]","Malzacher, P. (2015) Revision of the Oriental species of the genus Caenis Stephens (Insecta: Ephemeroptera: Caenidae). Stuttgarter Beitrage zur Naturkunde A, Neue Serie, 8, 27 - 47."]}

Caenis sp. 1 (Figs. 143–151) Materials examined. 1J imago, 1♀ imago, South India, Tamil Nadu, Madurai District, Vaigai river, 10°08′32′′N, 77°93′22′′E, 192 m, 1.VIII.2022, colls. P. Srinivasan & R. Isack (AMC /ZN/211, 212). Description. Male imago (Fig. 143). Measurements. Body length: 2.9 mm; forewing length: 1.9 mm; foreleg length: 1.8 mm; midleg length: 1 mm; hindleg length: 1.2 mm; cercus length: 6.7 mm. Ratios. Head (see Malzacher 2015; Fig. 4k): c: a = 2.2; a: b = 1.1; Leg: fore femur: fore tibia = 0.57; fore tibia: fore tarsus = 1.37; fore leg: hind leg = 1.5; segments of fore tarsus 1st: 2nd: 3rd: 4th: 5th = 1: 3.6: 2.1: 1.6: 0.9 Coloration. Head: Vertex light brownish. Antenna: scape and pedicel pale. Thorax: Prothorax mostly pale with dark brownish transverse band in the posterior margin. Mesonotum generally dark brownish; scutellum darkly pigmented with fin-shaped processes; mesonotal suture darkly pigmented; prosternum, mesosternum, and metasternum pale. Wings hyaline, costa, and subcostal veins reddish-brown. Legs whitish, except apical part of femora and tibiae with a dark brownish patch. Abdomen: Terga mostly colourless with a well-developed brownish transverse band and a longitudinal black stripe medially on terga III– VI (Fig. 144). Cerci translucent. Head (Fig. 145). Fore margin between lateral and frontal ocelli slightly bowed. Pedicel two times the length of scape. Base of the antennal flagellum slightly dilated. Thorax. Prosternal sclerites strong, forming an apically blunt isosceles triangle, without transverse strip. Foretarsus segments 2–3 each with a lateral and a median projections and segment 4 with an apico-median projection equipped with strong small spines (Fig. 146). Abdomen. Tergum II without a finger-like process. Lateral filaments short. Penis broad, with rounded lobes, hind margin with a well-developed medial incision, Penis mediolaterally with a tongue-shaped process. Forceps basally broadened with more or less parallel sides, consists of a long tuft of spines with a strong spine more or less fused with few thin spines (Fig. 147). Other genital details are missing. Female imago. Measurements. Body length: 3.7 mm; forewing length: 2.4 mm. Coloration is similar to that of males. Transverse band in terga III–VI strongly pronounced compared to that of males. Larva. Unknown. Egg. Length: 110–120 μm; width: 75–85 μm. Oval-shaped (Figs. 148, 149); chorion smooth with a flat epithema forming a coil of fine threads on the pole (Fig. 150); micropyle long, situated at the subequatorial plane with mouth not broadened, with well visible circular sperm guide (Fig. 151). Distribution. Vaigai river, Madurai, Tamil Nadu, India. Discussion. The unnamed species Caenis sp. 1 is similar to C. ulmeriana and C. limai by the shape of the forceps, but differs from them by the lateral and median projections in foretarsus segments 2–3 and an apico-median projection in segment 4 in the male imago (Malzacher 2015; Malzacher and Sangpradub 2020; Srinivasan et al. 2023). The eggs of Caenis sp. 1 distinguished from both C. ulmeriana and C. limai by the length of the micropyle (Malzacher and Sangpradub 2020; Srinivasan et al. 2023)., Published as part of Srinivasan, Pandiarajan, Sivaruban, T., Barathy, S. & Isack, Rajasekaran, 2023, Contribution to the knowledge of family Caenidae (Insecta: Ephemeroptera) from Madurai District, Tamil Nadu, pp. 39-75 in Zootaxa 5258 (1) on pages 67-69, DOI: 10.11646/zootaxa.5258.1.2, http://zenodo.org/record/7773275, {"references":["Malzacher, P. (2015) Revision of the Oriental species of the genus Caenis Stephens (Insecta: Ephemeroptera: Caenidae). Stuttgarter Beitrage zur Naturkunde A, Neue Serie, 8, 27 - 47.","Srinivasan, P., Sivaruban, T., Barathy, S. & Isack R. (2023) A new species of Caenis Stephens, 1835 and description of male subimaginal characters of Caenis americani Srinivasan et al. 2021 (Ephemeroptera: Caenidae) from the Western Ghats, South India. Aquatic Insects. [in press]"]}

Caenis hanleyi n. sp. (Figures 1–5) LSID urn:lsid:zoobank.org:act: 5A7C1E45-FC7E-414D-9A48-406E787E12EC Tasmanocoenis sp H (Suter, 1992) Tasmanocoenis sp H in part (Suter, 1999a) Type Material ( Deposited in the Museum and Art Gallery of Northern Territory ). Holotype: 1 Male imago and nymphal exuvium on three slides. Magela Ck at Ranger outlet pipe 12.68S 132.93E 19 May 1988, emerged on 27 May 1988; Identification no. ARR37, ARR38 and ARR39; coll. P. Suter (PS); NTMI011230. Paratypes: 1 male imago and nymphal exuvium on 4 slides. Same details as holotype; Identification no. ARR33, ARR34, ARR35 and ARR36; coll. PS; NTMI011231. 1 nymph on 2 slides. Magela Ck at Ranger outlet pipe 12.68S 132.93E 17 Feb 1988; Identification no. ARR28 and ARR29; coll. P. Dostine (PD): NTMI011232. 1 nymph in ethanol. Magela Ck downstream of pontoon 12.64S 132.90E 9 May 2019 JH; NTMI011233. 1 nymph in ethanol. Magela Ck upstream pool 12.67S 132.93E 2 Sept 2021 JH; NTMI011234. 1 nymph in ethanol. Nourlangie Ck 12.856S 132.777E 13 May 2021 JH; NTMI011235. Other Material Examined. Northern Territory 3 nymphs, Cooper Ck at Narbalek 12.3S 133.33E 27 May 1988 PS; 20 male imagoes 10 nymphs, Magela Ck at Ranger outlet pipe 12.68S 132.93E 19 May 1988 PS, 17 Feb 1988 PD; 1 nymph, Gulungul Ck at inlet to Gulungul Billabong 12.63S 132.88E 16 May 1988, April 1989 PS; 4 nymphs, Magela Ck at inlet to Mudginberri Billabong 12.60S 132.88E 18 May 1988, April 1989 PS; 2 nymphs, Radon Springs 12.75S 132.92E 18 May 1988 PS; 7 nymphs, Baroalba Springs 12.82S 132.87E April 1989 PS; 2 nymphs, Koolpin Ck 13.48S 132.58E 25 May 1988 PS; 1 nymph, Gulungul Ck at highway crossing 12.65S 132.867E 15 Oct 2006 Identification no. GCH152 CN J. Hanley (JH); 1 nymph, Coomalie Ck at road to Bachelor east of Lichfield National Park 13.0104S 131.1136E 24 Sept 2009 Identification no. JWA1959, PS, J. Webb (JW), J. Hawking (JH), M. Halsey (MH); 5 nymphs, Magela Ck downstream of pontoon 12.64S 132.90E 9 May 2019 JH; 11 nymphs, Magela Ck upstream pool 12.67S 132.93E 2 Sept 2021 JH; 1 nymph, Nourlangie Ck 12.856S 132.777E 13 May 2021 JH. Diagnosis. C. hanleyi can be characterised by the following combination of characters. In the male imagoes: body length 1.7–2.2 mm; base of antennal flagellum not dilated (Fig. 1d, 1c); penes with median concavity and rounded lateral lobes (Fig. 1f); styliger plate with apex straight (Fig. 1f); forceps long, broad and straight>7 times longer than terminal spines; apical tuft of four spines on an apical stalk (Fig 1f, 1g). In the nymphs, body length 2.2–2.5 mm; body colour dark brown with antennae, and legs dark (Fig. 2a, 2b, 2c, 4c); body surface covered with distinct short rounded triangular tubercles (Fig. 5b, 5c, 5d); segment II of maxillary palp shorter than segments I and III (Fig. 3b); labial palp with segment II long 1.5–1.6 x longer than segment III (Fig. 3c, 3d); left mandible with three apical teeth and an inner lateral tooth on outer incisors (Fig. 3f, 3h); anterior lateral margin of mesonotum lacking lateral projections (Fig. 4e); coxae of legs without small rounded processes; fore femur transverse row of 25 tracheal filaments which have multifid (2–4) tracheal branches (Fig. 5). Description Male imago (n=3). Body Length 1.7–2.2 mm; wing length 1.4–1.6 mm terminal filament length 3.5–3.8 mm. Head: Base of antennal flagellum not dilated (Fig. 1d, 1e). Antennal pedicel, scape and base of flagellum tinged brown; pedicel 1.7–3.5 x longer than scape, flagellum length 0.47–0.52mm (Fig.1d, e). Prosternum triangular with straight lateral sides, apex broadly rounded (Fig. 5a, 5b). Legs slender and delicate; forelegs longer than mid and hind legs; tarsomeres of foretarsus apically not broadened, foretarsal claws similar, both blunt and ovoid (Fig.1h); mid and hind tarsal claws dissimilar one blunt and one slender, curved and sharp. Tarsal segment formula of foreleg 2, 3=4, 5=1. Femora lacking apical markings. Leg ratios: Foreleg 1.00 (0.39–0.42 mm): 1.10–1.28: 0.79–0.87. Middle leg 1.00 (0.40–0.41 mm): 0.63–0.73: 0.49–0.50. Hind leg 1.00 (0.42–0.44 mm): 0.62–0.73: 0.48–0.52. Scutellum broad, posteriorly broadly rounded. Wings 1.94–2.0 x longer than wide (Fig. 1a), with hind margin lined with long hairs which are longest in anal and cubital region and short in radial region (Fig. 1b). Abdomen: Without markings on sternites, with lateral filaments on abdominal segments IV–VIII (difficult to see or may be dislodged in some specimens) (Fig. 1c). Sternite IX and genitalia (Fig. 1f); styliger plate rectangular length one third width, central sclerite dome shaped, lateral sclerites broad, wider than base of forceps, apophyses short slightly curved inwards; penes with median concavity and rounded lateral lobes. Forceps long, uniformly broad and straight (Fig. 1g), not curved; 7–10 x longer than apical spine length; 3.32–4.00x longer than wide, with tuft of four apical spines and surface covered with long setae/hairs. Three terminal filaments 3.50–3.85 mm long. Nymph (n=10). Body length: males 2.2–2.5mm; terminal filaments 2.0 mm; females 3.6 mm long. General body colour brown, without mottled markings (Fig. 4e). Head dark brown with light central area in the frontoclypeal region between antennae; antennae with scape, pedicel and base of flagellum brown (Fig. 2a); pedicel 0.06–0.07mm, 2.0–2.3 x length of scape, antennal length 0.76–1.14 mm long. Head covered in small triangular tubercles (Fig. 5b, c), genae not bulged. Mouthparts: Labrum broadly emarginate, width 2.0 x length with long setae along margins, long simple setae posterior to concavity and those along mid row bifid and pinnate (Fig. 3a). Left mandible (Fig. 3e) with long pinnate setae on outer margin, incisors paired, outer incisors with three apical teeth and a single tooth on inner margin, inner incisors with three teeth (Fig. 3h); prostheca robust slightly divided apically with long multifid setae; edge between prostheca and molars lined with short bristles; base of mandible with area of short tuberculate ornamentation. Right mandible (Fig. 3e) with long pinnate setae on outer margin; incisors paired, outer incisors with three teeth; inner incisors with two teeth (Fig. 3g); prostheca robust with multifid apical setae; inner margin of mandible with row of setae; base of mandible with area of short tuberculate ornamentation. Maxilla (Fig. 3b) galeo-lacinia with three apical teeth and row of setae on inner margin; base with a separate row of setae; maxillary palp three segmented, longer than galeo-lacinia, segment ratio 1.00 (0.07–0.08 mm): 0.66–0.78: 1.05–1.22. Labium (Fig. 3c, d) paraglossae longer than glossae; proximal segment of labial palp 1.33–1.70 x longer than broad; lateral margin with 12 short, robust pinnate setae; distal segment short, triangular; segment ratio 1.00 (0.0.07– 0.10 mm): 0.89–1.13: 0.48–0.73. Thorax: Pronotum brown without markings (Fig. 2b), covered with short triangular tubercles (Fig. 5e); antero-lateral margin with 1–2 short spine setae. Mesonotum without distinct markings, with short triangular tubercles on postero-lateral surface and linear rows on surface of wingpads (Fig. 5d). Legs all tinged brown with rows of rounded triangular tubercles, lacking coxal process. Foreleg (Fig. 2a) tinged brown, femur with transverse row of four long bifid setae and four short bifid setae (Fig.2i); tibia with three long setae on transverse surface, three spines on ventral surface, apical spine longest; dorsal surface with long fine hairs; tarsus with five spines on the ventral margin, dorsal and transverse surface with long fine hairs; tarsal claw long and slender, slightly curved and smooth, 0.52–0.61 x tarsus length (Fig. 2d). Mid leg (Fig. 2e) tinged brown; femur with row of 3–4 bifid setae; tibia with long blunt setae on dorsal surface; inner margin with five sharp spines; surface of segment covered with long fine hairs; tarsus with nine sharp spines on inner margin; long fine hairs on surface of segment, tarsal claw long and smooth, 0.56–0.62 x tarsal length (Fig.2f). Hind leg (Fig. 2g) tinged brown; dorsal surface with 2–3 spatulate setae; tibia with long blunt setae on dorsal surface, inner margin with approx. six sharp spines; surface of segment with long fine hairs; tarsus with dual row of spine setae on inner margin and surface with long fine hairs; tarsal claw long, slender, curved with comb of fine, short setae in basal half, 0.51–0.54 x tarsal length (Fig.2h). Ratios of segments: Foreleg 1.00 (0.40–0.42 mm): 0.60–0.70: 0.62–0.67: 0.35–0.38. Middle leg 1.00 (0.37 mm): 0.72: 0.55. Hind leg 1.00 (0.39 mm): 0.80: 0.64. Femur length to width ratios, fore femur 2.5–3.0; mid femur 3.0–3.5; hind femur 2.9–3.4. Abdomen: Tergites brown with light square medial marking on segment VIII, segments VII and X light brown, segment IX dark brown. Posterior margin of abdominal tergite I without setae; tergite II with short triangular process between operculate second gills; hind margins of tergites VII and VIII with numerous long setae; postero-lateral spines on abdominal segment IV–IX (Fig. 4a). Dorsal surface with small triangular tuberculate ornamentation. Sternite of abdominal segment IX with convex posterior margin. Caudal filaments with basal segments with short lateral setae, 0.4 x segment length but with intersegmental setae equal to segment length (Fig. 4b); mid–apical segments of caudal filaments with lateral and intersegmental setae long 0.6 x segment length (Fig. 4c). Gills: First gill two segmented with apical segment 2.0–2.5 x longer than basal segment (Fig. 4d). Second gills operculate 1.3x longer than wide (Fig. 2j), with outer and posterior margins lined with long pinnate setae each separated by short bifid setae (Fig. 2k); inner margin with shorter setae, outer margin slightly serrated; mesal ridge with approx. eight short bifid setae basally and three long pinnate setae (Fig. 2l), and short triangular tubercles along its posterior length; gill dorsal surface covered with short triangular tubercles and netmesh (Fig. 5f). Submarginal row of microtrichia running closely to lateral margin, ending in middle of hind margin of gill (Fig. 2j); microtrichia simple, fringed apically (Fig. 2k). Third to sixth gill oval with>20 filaments each with multifid (2–3) tracheal branches (Fig. 5a). Etymology. Named in honour of Julie Hanley who has supported our work in the Alligator Rivers region of the Northern Territory with fresh material whenever requested. Ecological observations. Lotic, in the main streams in slow flowing water where there an accumulation of fine organic material. Specimens were also collected from organic rich, highly coloured, isolated pools at Radon Springs where daytime temperature exceeded 30 oC in May 1988., Published as part of Suter, Phillip J., Mynott, Julia H. & Webb, Jeff M., 2023, The first record of Caenis Stephens, 1835 in Australia (Ephemeroptera: Caenidae) with descriptions of two new species, pp. 477-488 in Zootaxa 5228 (4) on pages 479-486, DOI: 10.11646/zootaxa.5228.4.6, http://zenodo.org/record/7540068, {"references":["Suter, P. J. (1992) Taxonomic key to the Ephemeroptera (Mayflies) of the Alligator Rivers Region, Northern Territory. Open File Record 96. Supervising Scientist for the Alligator Rivers Region, Sydney, 112 pp."]}

Caenis binda n. sp. (Figure 5c, 6) urn:lsid:zoobank.org:act: BCE71B49-68E7-4316-87E5-45E25F23759F Tasmanocoenis Sp H in part, Suter 1999a Type Material (Deposited in the Queensland Museum). Holotype: Male imago on slide. Queensland (Qld), Freshwater Creek by Crystal Cascades caravan park off Redlynch Intake Road; 16.5833E, 145.6978S; 3 July 2008; coll. JM Webb (JMW), JH Hawking (JHH), PS, S. Moore (SM); LaTrobe University (LTU) accession no. JWA712a; T258326. Paratypes: 2 male imagoes on slides details as for holotype LTU accession no. JWA712b–c; T258327 and T258328; 1 male imago in ethanol, Granite Creek at Mareeba to Mt Malloy Road; 16.9847E, 145.4192S; 1 July 2008; JMW, JHH, PS, SM; LTU accession no. JWA1718; T258329; 1 male imago in ethanol Freshwater Creek by Crystal Cascades caravan park off Redlynch Intake Road; 16.5833E, 145.6978S; 26 June 2008; JMW, JHH, PS, SM; University (LTU) accession no. JWA1728; T258330; 1 male imago in ethanol Babinda Creek at A1 (Bruce Highway); 17.3643E, 145.9156S; 27 June 2008; JMW, JHH, PS, SM; LTU accession no. JWA1706; T258331. Other Material Examined. One male imago, Queensland. Freshwater Creek by Crystal Cascades caravan park off Redlynch Intake Road; 16.5833E, 145.6978S; 3 July 2008; JMW, JHH, PS, SM; LaTrobe University (LTU) accession no. JWA1601. One male imago, Granite Creek at Mareeba to Mt Malloy Road; 16.9847E, 145.4192S; 1 July 2008; JMW, JHH, PS, SM; LTU accession no. JWA1719. One male imago, Freshwater Creek by Crystal Cascades caravan park off Redlynch Intake Road; 16.5833E, 145.6978S; 3 July 2008; JMW, JHH, PS, SM; LaTrobe University (LTU) accession no. JWA1727. One male imago, Babinda Creek at A1 (Bruce Highway); 17.3643E, 145.9156S; 27 June 2008; JMW, JHH, PS, SM; LTU accession no. JWA1705. One male imago, Babinda Creek at A1 (Bruce Highway); 17.3643E, 145.9156S; 27 June 2008; JMW, JHH, PS, SM; LTU accession no. JWA1707. One male imago, Granite Creek at Mareeba to Mt Malloy Road; 16.9847E, 145.4192S; 1 July 2008; JMW, JHH, PS, SM; LTU accession no. JWA1717. 1 male imago. Lacey’s Creek at Cassowary Road (El Arish Mission Beach Road); 17.8512E, 146.0644S; 2 July 2008; JMW, JHH, PS, SM; LTU accession no. JWA1726. Diagnosis. C. binda can be characterised by the following combination of characters. In the male: body length 1.7–1.8 mm; base of antennal flagellum not dilated (Fig. 6c, 6d); penes with median concavity and lobes broad, rectangular (Fig. 6b) styliger plate length 0.6 times width (Fig. 6b); lateral sclerite short, narrow, triangular (Fig. 6b); forceps long and narrow, tapering from base to apex, 5.8 times longer than mid width (Fig. 6c); forceps with five apical bristles with one very long, three mid length and one short (Fig. 6c); forceps length 2–3 times longer than longest apical bristle; abdomen lacking lateral processes and femora with apical dark marking. Description Male Imago (n=6): Body Length 1.7–1.8 mm; wing length 1.6–1.9 mm; terminal filament length 3.8–4.3 mm. Head: Base of antennae not dilated; pedicel 1.4–1.8 x longer than scape, flagellum length 0.4–0.5 mm (Fig. 6d, e). Prosternum triangular with straight lateral sides, apex broadly rounded (Fig. 5c). Legs slender and delicate; forelegs longer than mid and hind legs; tarsomeres of fore tarsus apically not broadened, fore tarsal claws similar, both blunt and ovoid (Fig. 6g); mid and hind tarsal claws dissimilar one blunt and one slender, curved and sharp. Tarsal segment formula of foreleg 2, 4, 3, 5, 1. Femora of legs with dark apical elongate spot (Fig. 6f). Foreleg femur 0.31–0.44 mm long, tibia 1.4–1.5 x femur length, tarsus 1.1–1.4 x femur length. Mid leg length 0.34–0.36 mm, tibia 0.7–0.8x femur length, tarsus 0.4–0.5x femur length. Hind femur length 0.34–0.36 mm, hind tibia 0.7 x femur length, hind tarsus 0.5–0.7 x femur length. Scutellum broad, posteriorly with indentation, broadly rounded. Wings 2.0–2.2 x longer than wide (Fig. 6a), with hind margin lined with long hairs which are longest in anal and cubital region and short in radial region. Abdomen without markings on sternites, sternites VI–VIII lacking lateral filaments. Penis with median concavity and each lobe rectangular. Forceps long, broad, tapering from base to apex and straight (Fig. 6c), not curved; 2–3 x longer than longest apical spine length; at base 3 x longer than wide, at mid length 5.8 x longer than wide, at apex 11.2 x longer than wide with tuft of five apical spines, one very long and three approx. half-length of longest spine and 1 very short; surface covered with long setae/hairs. Three terminal filaments 3.8–4.3 mm long. Nymph unknown. Etymology. From the traditional owners’ (the Yidinji people) name ‘binda’ meaning waterfall as a description of the ‘Cascades’ on Freshwater Creek near Cairns, Queensland (www.cairnsconnect.com accessed 22 September 2022).

Male imagos of Caenis from Brazil (adapted from Domínguez et al. 2006) 1. Apex of the forceps sharp and sclerotized................................................................. 2 - Apex of the forceps rounded........................................................................... 5 2(1). Forceps narrowing gradually toward the apex.............................................................. 3 - Forceps sharpening abruptly at the apex................................................................... 4 3(2). Surface of the forceps without setae with 3 subapical denticles; lobes of the penis fused, without vestige of a dividing groove (Da-Silva, 1993: Fig. 4).................................................................... Caenis cuniana - Forceps generally with small tubercles and setae on outer basal margin; forceps 7.3–9.5 times longer than width at the middle; apophyses strongly developed, wide and long (Molineri et al. 2011: Figs 3, 5, 6A–F)................... C. teipunensis 4(2). Forceps approximately six times longer than width at half length; about six setae present on ventral surface (Malzacher, 1986: Figs 5B, C, 11)............................................................................ C. candelata - Forceps approximately 9-11 times longer than width at half length, approximately 15-20 setae present on ventral surface (Malzacher, 1986: Figs 5A, 10).................................................................. C. fittkaui 5(1). Finger-like median process present in abdominal tergum II; fore leg twice as long as hind leg or longer; forceps and sclerites of the genitalia strongly colored........................................................................... 6 - Abdominal tergum II without median projections (but lateral projections may be present); fore leg at most 1.8 times the length of hind leg; forceps and sclerites of the genitalia nearly uncolored)............................................. 7 6(5). Lateral filaments of abdominal segments relatively short; lobes of penis short and laterally rounded; apophyses of the styliger sclerite long and thin, somewhat distanced from the base of the forceps (Malzacher, 2001: Figs 7A–E)...... C. plaumanni - Central sclerite of styliger elongated; apophyses of styliger sclerite broad and short; penis whitish with rounded lateral lobes (Molineri & Malzacher, 2007: Figs 96–98).......................................................... C. uruzu 7(5). Lobes of the penis totally fused, without a median groove.................................................... 8 - Groove separating the lobes of the penis visible............................................................ 9 8(7). Forceps somewhat curved toward median line; without trichomes or minute spines at apex; posterior margin of styliger plate more or less straight; penis rounded and narrow at the base (Pereira & Da-Silva, 1990: Fig. 2)................ C. cigana - Forceps curved toward median line, covered with trichomes with 2–3 minute spines at apex; posterior margin of styliger plate short convex; penis square-shaped, not narrow at base.................................. Caenis marataoan sp. nov. 9(7). Penis with laterally protruding lobes.................................................................... 10 - Lobes of penis very short and not or only slightl y protruding................................................ 13 10(9). Posterior margin of styliger plate straight or rounded....................................................... 11 - Posterior margin of styliger plate subtriangular............................................................ 12 11(10). Fore margin of the styliger sclerite convex; apophyses of styliger sclerite bent inwards (Malzacher, 2001: Figs 9A–I).................................................................................................. C. tenella - Fore margin of the styliger sclerite straight; apophyses of styliger sclerite pointed and straight (Lima et al. 2015b: Figs 1C, D)........................................................................................ C. gaucha 12(10). Apical margin of penis convex; apophyses of the styliger sclerite bent inwardly, fore margin of the styliger sclerite concave (Malzacher, 1990: Figs 1A, B)............................................................... C. pflugfelderi - Apical margin of penis straight; apophyses of the styliger sclerite pointed and straight, fore margin of the styliger sclerite straight (Alba-Tercedor & Mosquera, 1999: Figs 1, 4)............................................... C. chamie 13(9). Lobes of the penis very short and swollen at base; styliger plate usually covering the penis; prosternal triangle narrow and triangular, usually closed toward apex (Malzacher, 1986: Figs 13A, 16, 18A, B).......................... C. sigillata - Lobes of the penis relatively long; styliger plate not covering penis; prosternal triangle broad and usually open toward apex.................................................................................................. 14 14(13). Prosternal triangle very broad and open anteriorly; apex of genital forceps rounded with margins ornamented with small wartlike bumps; basal dilation of the antennal bristle about 1.5 times the length of the pedicel (Malzacher, 1986: Figs 12E, 13C, 17, 18C)............................................................................... C. quatipuruica - Prosternal triangle tapered and open anteriorly; apex of forceps without ornamented margins; basal dilation of the antennal bristle shorter than the length of the pedicel (Malzacher, 1986: Figs 12C, 13B, 15, 18D–F).................... C. reissi, Published as part of Nascimento, Stênio R. S., Rodrigues, Jackson A. O., Ale-Rocha, Rosaly & Lima, Lucas R. C., 2022, New species and records of Caenidae Newman, 1853 (Insecta: Ephemeroptera) from Northeastern Brazil, pp. 110-122 in Zootaxa 5133 (1) on pages 119-120, DOI: 10.11646/zootaxa.5133.1.5, http://zenodo.org/record/6521359, {"references":["Dominguez, E., Molineri, C., Pescador, M. L., Hubbard, M. D. & Nieto, C. (2006) Ephemeroptera of South America. In: Adis, J., Arias, J. R., Rueda-Delgado, G. & Wantzen, K. M. (Eds.), Aquatic biodiversity of Latin America. ABLA Series. Vol. 2. Pensoft, Sofia, Moscow, pp. 1 - 646.","Da-Silva, E. R. (1993) Descricao do imago macho de Caenis cuniana Froehlich, com notas biologicas (Ephemeroptera, Caenidae). Revista Brasileira de Zoologia, 10 (3), 413 - 416. https: // doi. org / 10.1590 / S 0101 - 81751993000300007","Molineri, C., Grillet, M. E., Nieto, C., Dominguez, E. & Guerrero, E. (2011) New species and records for the mayfly families Caenidae, Leptohyphidae and Coryphoridae (Ephemeroptera, Pannota) from Venezuelan Guayana's uplands. Zootaxa, 2750 (1), 39 - 50. https: // doi. org / 10.11646 / zootaxa. 2750.1.4","Malzacher, P. (1986) Caenidae aus dem Amazonasgebiet (Insecta, Ephemeroptera). Spixiana, 9, 83 - 103.","Malzacher, P. (2001) South and Central American Caenis species with rounded forceps tips (Insecta: Ephemeroptera: Caenidae). Stuttgarter Beitrage zur Naturkunde, 626, 1 - 20. https: // doi. org / 10.1080 / 01650424.2012.713112","Molineri, C. & Malzacher, P. (2007) South American Caenis Stephens (Ephemeroptera, Caenidae), new species and stage descriptions. Zootaxa, 1660 (1), 1 - 31. https: // doi. org / 10.11646 / zootaxa. 1660.1.1","Pereira, S. M. & Da-Silva, E. R. (1990) Nova especie de Caenis Stephens, 1835 do sudeste do Brasil (Ephemeroptera, Caenidae). Boletim do Museu Nacional (Rio de Janeiro), Zoologia, 341, 1 - 8.","Lima, L. R. C., Molineri, C. & Pinheiro, U. (2015 b) A new species of Caenis Stephens, 1836 (Ephemeroptera: Caenidae) from Southern Brazil. Zootaxa, 3941 (4), 589 - 592. https: // doi. org / 10.11646 / zootaxa. 3941.4.8","Malzacher, P. (1990) Neue Arten der Eintagsfliegen-Familie Caenidae (Insecta, Ephemeroptera) aus Sudamerika. Studies on Neotropical Fauna and Environment, 25, 31 - 39. https: // doi. org / 10.1080 / 01650529009360799","Alba-Tercedor, J. & Mosquera, S. (1999) Caenis chamie, a new species from Colombia (Ephemeroptera: Caenidae). Pan- Pacific Entomologist, 75 (2), 61 - 67."]}

Caenis chamie Alba-Tercedor & Mosquera, 1999 (Figs 6E, F) Caenis chamie Alba-Tercedor & Mosquera, 1999: 61; Lima et al. 2015a: 3; Lima & Boldrini, 2016: 3. Distribution. Colombia. Brazil: states of Goiás, Pernambuco and Roraima. New record: Piauí State. Material examined. 26 ♂ imagos, Brazil, Piauí State, Castelo do Piauí municipality, Rio Poti, S05°11’16.7”, W41°42’34.4”, 177 m a.s.l., 12.iii.2016, Lima, L. R. C. col. (CEHJ). One nymph, Brazil, Piauí State, Castelo do Piauí municipality, Cachoeira das Arraias, S05°11’28.5”, W41°42’03.2”, 174 m a.s.l., 12.iii.2016, Lima, L. R.C. col. (CEHJ). 14 ♂ imagos (light trap), Brazil, Piauí State, Alto Longá municipality, Longá River, Cachoeira da Campeira, S5°11’45.1” W42°15’33.9”, 177 m a.s.l., 27.iv.2017, Moreno, L.A.S. col. (CEHJ). Comments. Caenis chamie can be characterized, among other characters, by the straight hind margin of penis, genital sclerites sclerotized and discernible, and styliger plate projected, covering entirely the penis (adapted from Alba-Tercedor & Mosquera 1999)., Published as part of Nascimento, Stênio R. S., Rodrigues, Jackson A. O., Ale-Rocha, Rosaly & Lima, Lucas R. C., 2022, New species and records of Caenidae Newman, 1853 (Insecta: Ephemeroptera) from Northeastern Brazil, pp. 110-122 in Zootaxa 5133 (1) on pages 117-118, DOI: 10.11646/zootaxa.5133.1.5, http://zenodo.org/record/6521359, {"references":["Alba-Tercedor, J. & Mosquera, S. (1999) Caenis chamie, a new species from Colombia (Ephemeroptera: Caenidae). Pan- Pacific Entomologist, 75 (2), 61 - 67.","Lima, L. R. C., Salles, F. F. & Pinheiro, S. (2015 a) New records of mayflies (Ephemeroptera: Insecta) from Pernambuco state, northeastern Brazil. Check List, 11, 1 - 7. https: // doi. org / 10.15560 / 11.3.1652","Lima, L. R. C. & Boldrini, R. (2016) First records of small squaregilled mayflies (Ephemeroptera, Caenidae) from the state of Roraima, Northern Brazil. Check List, 12 (4), 1 - 5. https: // doi. org / 10.15560 / 12.4.1919"]}

Caenis marataoan Nascimento & Lima sp. nov. (Figs 2A–E, 3A–E, 4A–C, 5A–C). Diagnosis. This species can be characterized by the following combination of characters in the imagos: 1) male body length 1.5–2.0 mm, female body length 2.5–2.8 mm; 2) base of antennal flagellum not dilated; 3) forceps apically rounded, covered with trichomes, with 2–3 minute spines at apex (Figs 2B–E); 4) styliger plate short with posterior margin convex (Fig. 2A); 5) penis square-shaped, fused and not laterally projected; ventral surface without tubercles and groove (Fig. 2A); 6) eggs oval-shaped; micropyle linear with narrow and long micropylar canal, preceded by an oval sperm guide (Figs 5A, B). Description. Male imago. Body length: 1.5–2.0 mm; forewing: 1.4–1.8 mm; foreleg: 1.4–1.5 mm; hind leg: 0.8–1.1 mm; cercus: broken off. Ratios. Foreleg 1.2–1.8 × the length of hind leg. Ratio of first segment of the foretarsus length to 2 nd:3 rd:4 th:5 th = 0.2:0.3–0.4:0.3–0.5:0.5–0.7. Genitalia: forceps length 2.7–3.5 × the width at half length; distance between the extreme lateral points of the forceps bases to forceps length = 2.3–3.0. Coloration. Head: whitish shaded with gray in dorsal view (Fig. 2A); venter of head whitish (Fig. 2C). Antenna: scape and pedicel whitish, flagellum hyaline (Figs 2A–C). Thorax. Prothorax yellowish translucent shaded with gray on lateral and posterior margin (Figs 2A–D). Meso- and metanotum yellowish shaded with gray on carinae; mesonotum yellowish; pleurae and sterna paler. Wing membrane hyaline, veins translucent except C, Sc and Rs grayish. Legs. Foreleg whitish translucent with coxa and femur shaded with gray. Middle and hind legs whitish translucent. Abdomen. Abdominal segments I–VIII translucent white, IX–X yellowish; abdominal terga I–II with a blackish line on posterior margin (Figs 2A, E). Sterna translucent white with segments IX–X yellowish (Fig. 2C). Pleura white (Fig. 2B). Genitalia. Sternum IX with weak and uncolored sclerites (Fig. 2C). Forceps, penis and caudal filaments translucent white (Figs 2B, C). Morphology. Antenna: Base of antennal flagellum not dilated. Thorax. Lateral margins straight, not protruding; prosternal longitudinal ridges forming a triangle shaped structure, open anteriorly and with straight lateral margins (Fig. 2A). Abdomen. Lateral filaments and finger-like process on tergum II lacking. Genitalia. Styliger plate rectangular, not sclerotized, covering the basal 2/3 of penis; anterior margin almost straight and posterior margin slightly convex; central sclerite circular, apophyses short and pointed, basolateral and lateral sclerites weakly discernible (Fig. 3A). Forceps, apically rounded, densely covered with trichomes, and not fused to lateral margins of styliger plate (Figs 3A–E). Penis square-shaped, fused and not laterally projected; ventral surface without tubercles and groove (Fig. 3A). Female imago. Body length: 2.5–2.8 mm; forewing: 2.2–2.3 mm; foreleg: 1.4–1.8 mm; cercus: broken off. Thorax: same as males except dark lines on sutures of mesonotum (Fig. 4A); katepisternum not paler than rest of mesopleural sclerites (Fig. 4B). Abdomen: same as males except abdomen with segments I–VI shaded with gray; abdominal sternum IX with posterior margin straight, not projected (Fig. 4A, C). Lateral filaments absent. Egg. Length: 102–114 μm; width: 62–68 μm. Coloration light yellow. Oval-shaped with length 1.7–1.9 × width. Chorion surface with small pores. Micropyle linear with narrow and long micropylar canal, preceded by an oval sperm guide (Figs 5A, B). Two polar caps hood-like (multithread with short filaments and small knobs). (Figs 5A, C). Nymph. Unknown. Etymology. The specific epithet is given to this species as a noun in apposition, and refers to the Marataoan River, type locality of the new species. Type material. Holotype: one ♂ imago (genitalia on slide) from Brazil, Piauí State, Barras municipality, Marataoan River, Pesqueiro, S4°15’13.7”, W42°17’19.1”, 84m, 18.iv.2017, Lima, L. R.C. col. (INPA-EPH000030). Paratypes: 75 ♂ imagos (light trap), same data as holotype (INPA-EPH000031); eight ♂ imagos and two ♀ imagos (light trap), same data as holotype except 10.x.2015 (INPA-EPH000032). Two ♂ imagos (light trap) from Brazil, Piauí State, Batalha municipality, Longá River, Cachoeira do Urubu, Pedra Dela, S3°54’51.7”, W42°06’37.8”, 68m, 10.x.2015, Lima, L. R. C. col. (UFVB000425). 15 ♂ imagos (light trap), from Brazil, Piauí State, Barras municipality, Longa River, near the PI-113 brigde, S4°12’08.4”, W42°14’21.2”, 74m, 18.iv.2017, Lima, L. R. C. col. (UFVB000426)., Published as part of Nascimento, Stênio R. S., Rodrigues, Jackson A. O., Ale-Rocha, Rosaly & Lima, Lucas R. C., 2022, New species and records of Caenidae Newman, 1853 (Insecta: Ephemeroptera) from Northeastern Brazil, pp. 110-122 in Zootaxa 5133 (1) on page 112, DOI: 10.11646/zootaxa.5133.1.5, http://zenodo.org/record/6521359

Caenis fittkaui Malzacher, 1986 (Figs 6G, H) Caenis fittkaui Malzacher, 1986: 91; Salles et al. 2010: 304; Shimano et al. 2011: 245; Lima et al. 2015a: 3; Lima & Boldrini, 2016: 3; Lima et al. 2016b: 215. Distribution. Brazil: states of Bahia, Espírito Santo, Mato Grosso, Pará, Pernambuco, and Roraima. New record: Piauí State. Material examined. One ♂ imago, Brazil, Piauí, Campo Maior, Lagoa do Arain, S4°50’26.1”, W42°10’50.1”, 119 m a.s.l., 21.ix.2014, Lima, L. R. C. col. (CEHJ). One ♂ imago, Brazil, Piauí, Piracuruca municipality, Rio Piracuruca, Prainha, S03°56’15.9”, W41º42’36.1’’, 74 m a.s.l., 10.xii.2015, Silva, A.P.S. col. (CEHJ). One ♂ imago, Brazil, Piauí, Barras municipality, Rio Marataoan, Pesqueiro, P 1, S04°15’13.7”, W42°17’19.1”, 84 m a.s.l., 10.xii.2015, Silva, A.P.S. col. (CEHJ). Comments. Caenis fittkaui can be differentiated from other species of Caenis by the following characters: apex of forceps sharp and directed posteriorly, lobes of penis fused, forming a rounded head and with small tubercles distributed on the ventral surface (adapted from Malzacher 1986)., Published as part of Nascimento, Stênio R. S., Rodrigues, Jackson A. O., Ale-Rocha, Rosaly & Lima, Lucas R. C., 2022, New species and records of Caenidae Newman, 1853 (Insecta: Ephemeroptera) from Northeastern Brazil, pp. 110-122 in Zootaxa 5133 (1) on pages 118-119, DOI: 10.11646/zootaxa.5133.1.5, http://zenodo.org/record/6521359, {"references":["Malzacher, P. (1986) Caenidae aus dem Amazonasgebiet (Insecta, Ephemeroptera). Spixiana, 9, 83 - 103.","Salles, F. F, Nascimento, J. M. C., Massariol, F. C., Angeli, K. B., Barcelos, S. P., Rudio, J. A. & Boldrini, R. (2010) Primeiro levantamento da fauna de Ephemeroptera (Insecta) do Espirito Santo, Sudeste do Brasil. Biota Neotropica, 10 (1), 293 - 307. https: // doi. org / 10.1590 / S 1676 - 06032010000100025","Shimano, Y., Salles, F. F. & Cabette, H. S. R. (2011) Ephemeroptera (Insecta) from east of Mato Grosso State, Brazil. Biota Neotropica, 11, 239 - 253. https: // doi. org / 10.1590 / S 1676 - 06032011000400021","Lima, L. R. C., Salles, F. F. & Pinheiro, S. (2015 a) New records of mayflies (Ephemeroptera: Insecta) from Pernambuco state, northeastern Brazil. Check List, 11, 1 - 7. https: // doi. org / 10.15560 / 11.3.1652","Lima, L. R. C. & Boldrini, R. (2016) First records of small squaregilled mayflies (Ephemeroptera, Caenidae) from the state of Roraima, Northern Brazil. Check List, 12 (4), 1 - 5. https: // doi. org / 10.15560 / 12.4.1919","Lima, L. R. C., Knapp, W. & Docio, L. (2016 b) New records of mayflies (Insecta: Ephemeroptera) from Bahia State, Northeastern Brazil. Entomotropica, 31, 212 - 220."]}

Caenis maduraiensis Balasubramanian and Muthukatturaja, new species (Figs. 1���3, 5���30) Type material. Holotype (in ethanol): male imago (reared from nymph) (Reg.No. SRC/ ZSI-I/E 469) from India, Vandiyur pond, Madurai district, Tamil Nadu state, 9.viii. 2019, 124 m, 09��54���51��� N, 78��10���52��� E, Balasubramanian & Muthukatturaja Cols. Paratypes (in ethanol): one female imago (reared from nymph) (Reg.No. SRC/ ZSI-I/E 470) and 5 mature nymphs (Reg.No. SRC/ ZSI-I/E 471), same data as holotype. Balasubramanian & Muthukatturaja Cols. Additional material (ZMTC). 156 male imago (reared from nymph), 254 female imago (reared from nymph) and 245 mature nymphs, India, Vandiyur pond, Madurai district, Tamil Nadu state, 19.viii. 2019, 124 m, 09��54���51��� N, 78��10���52��� E, Balasubramanian & Muthukatturaja Cols. Diagnosis. Caenis maduraiensis sp. nov.: Nymph: (i) anterior margin of labrum with row of long bipectinate setae laterally and a group of highly fringed setae behind emargination; (ii) fore femora with transverse row of bifid spines; middle and hind femora with sparse bifid spines; (iii) hind claw long, slender and hooked with row of denticles; (iv) abdominal tergum II with pointed medial projection and pointed teeth on the posterior margin. Imago: (i) prosternal triangle with slightly concave sides, tip acutely pointed; (ii) tarsomere I extremely short; (iii) tarsomere II apically with tongue-shaped projections on single side; (iv) apical part of forceps narrowed to the tip, with a long apical spine, and few trichomes on surface; (v) cross veins of forewing arranged singly except in R 1 and R 4; (vi) MP forked at near 1/3 of distance from base to margin; (vii) fore tibia two times longer than femur and (viii) female subanal plate apically truncated. Mature nymph (in 95% ethanol) (Figs. 1, 5���19): Body length (excluding cerci) 3.1���3.4 mm; cerci length 3.5���4.0 mm; median caudal filament 4.2���4.5 mm; length of head 0.4 mm; width of head 0.7 mm; antennae length 1.3 mm; length of fore femora/ tibia/ tarsi/ claw (mm) 0.7/0.5/0.3/0.2; length of middle femora/ tibia/ tarsi/ claw (mm) 0.6/0.37/0.25/0.18 and length of femora/ tibia/ tarsi/ claw (mm) viz., 0.65/0.6/0.4/0.15. General body coloration yellowish brown dorsally and pale ventrally, mature specimens generally paler; legs pale brown. Head brownish yellow; scape and pedicel of antennae pale brown without hairs, flagellum translucent; labrum (Fig. 5) broadly emarginated, dorsum with long setae, anterior margin with row of bipectinate setae longer laterally and a group of highly fringed setae behind emargination; mandibles (Figs. 6, 7) with broad incisors, outer margin of mandibles with long thin setae, left mandible with 7 thin setae below the molar, with elevated hump between prostheca and molar; maxillae (Figs. 8, 9) with 3 prominent teeth on galea���lacinia, ventral base of inner margin of galea with tuft of thin setae, distal portion of cardo with cluster of bipectinate stout setae, maxillary palp 3 segmented, segment I broad, segment I and II subequal in length, segment III longer, inner margin of segment III with row of 13 bipectinate setae; hypopharynx (Fig. 10): anterior margin of lingua with long setae, superlingua with small hair-like setae at anterior margin; labium with glossae (Fig. 11) ovate with stout spines at outer margin, mesal margin of glossae with thin setae, inner and outer margin of paraglossae with thin spines directed anteriorly, labial palp 3 segmented, segment II slightly longer than segment I, segment III short; outer margin of segment II with stout spines, outer margin of segment I with row of bipectinate setae, segment III triangular with 2 rows of stout setae ventrally, inner margin of segment III with row of stout spines. Thorax brownish yellow; lateral margins of pronotum convex, anterolateral margins with pair of spine-like setae and wider than posterolateral margins. Legs pale brown covered with scales, tibiae and tarsi light pale. Foreleg (Fig. 12): trochanter with transversal row of stout spines; outer margin of femur with few setae and spines, near �� of dorsal surface with transversal row of bifid spines, inner margin with few stout spines, �� of dorsal surface with few long hairs; tibia with 3 bifid spines at mesal margin, inner distal margin with long bipectinate setae; few long hairs on tibia; tarsi with row of stout spines on inner margin, mesal margin with bipectinate spine; few long hairs on tarsi; claw long, slender and slightly hooked. Middle leg (Fig. 13): trochanter with two bifid spines; outer margin of femora with long spines, �� of inner margin with stout spines and remainder with bifid spines, dorsal surface with sparse bifid spines; inner margin of tibia with row of stout spines; �� of tarsi with short bipectinate setae at mesal margin, claw long, slender and slightly hooked. Hindleg (Fig. 14): trochanter with bifid spine; inner and outer margin of femur with long spines, �� of dorsal surface with few bifid spines; inner margin of tibia with row of stout spines, outer margin with thin setae; tarsi similar to midleg; claw (Fig. 15) long, slender and hooked with row of denticles. Abdomen. Terga VII���X yellowish brown; tergum II with pointed medial projection and pointed teeth on the posterior margin; posterior margin of terga VII���IX with row of long setae; abdominal sterna III���IX pale brown. Gills (Figs. 16���19): pale brown; gill I (Fig. 16) 2-segmented, distal segment 4 times longer than proximal segment; gill II (Fig. 17) brown, covered with scales; margins evenly covered with long setae, inner margin with row of fringed setae; gills 3���6 (Figs. 18, 19) roughly triangular and with more than 15 multifid fimbriae with more than 2 branches; pigmented areas of the gill surface alternating with non-pigmented transparent tracheae. Cerci pale brown with whorls of setae in each segment. Male Imago (in alcohol) (Figs. 2, 20���27): body length, 2.2���2.5 mm; cerci length, 8.8���9.1 mm; terminal filament, 9.6���9.9 mm; length of head 0.15 mm, width of head 0.5 mm; length of antenna 0.5 mm; length of forewing 1.85���2.05 mm; width of forewing 1.0��� 1.3 mm; dorsal diameter of eye 0.1 mm; distance between compound eyes 0.125 mm; length of segments in foreleg femur/ tibia/ tarsus (mm): 0.45/0.9/0.6; length of tarsal segments 1 to 5 (mm): 0.03/0.28/0.12/0.11/0.06. Head (Fig. 20) pale brown, anterior margin and area around antennal base pale brown; scape and pedicel of antennae pale brown, flagellum translucent. Thorax yellowish brown; prosternal triangle with slightly concave sides, tip acutely pointed (Fig. 21). Legs: foreleg (Fig. 23���25) pale brown, middle and hindleg translucent; fore femur brown, tibia washed brown and two times longer than femur; tarsomere I extremely short; tarsomere II apically with tongue-shaped projections on single side; tarsomeres II���IV provided with short spines (Figs. 24���25); segment V short. Wings: Forewings (Fig. 22) oval, with few cross veins; cross veins arranged singly except in R 1 and R 4; two cross veins at near �� of R; MP forked at near 1/3 from base; CuA not forked. Veins C and Sc brown basally and washed brown distally, remaining veins translucent.Abdomen: tergum I���VI pale brown remaining terga translucent; sterna whitish. Genitalia (Fig. 26) pale brown, penis lobes completely fused and produced laterally; styliger sclerite broad with short apophyses; forceps slender, apical part narrowed to the tip, with a long apical spine, and many trichomes on surface (Fig. 27); cerci and terminal filament translucent with whorls of setae in each segment. Female Imago (in alcohol) (Figs. 3, 28���30): body length, 4.3���4.6 mm; cerci length, 3.2���3.5 mm; terminal filament, 4.0��� 4.3 mm; length of head, 0.3 mm, width of head, 0.8 mm; length of antenna, 0.6 mm; length of forewing, 3.2���3.5 mm; width of forewing, 1.4���1.7 mm; distance between compound eyes, 0.58 mm; dorsal diameter of eye, 0.12 mm; length of segments in foreleg femur/tibia/tarsus (mm): 0.52/0.73/0.63; length of tarsal segments (mm): 0.035/0.35/0.12/0.15/0.075. Head (Fig. 28) pale brown; anterior margin and area around antennal base pale brown; scape and pedicel of antennae pale brown, flagellum translucent. Thorax yellowish brown; prosternal triangle with concave sides, tip acutely pointed (Fig. 29). Legs: foreleg pale brown remainders translucent; tarsomere II much longer than others. Wings: veins C and Sc brown basally and washed brown distally, remaining veins translucent. Abdomen: terga I���VI pale brown remaining terga translucent; sterna whitish; cerci and median terminal filament translucent; posterior margin of sternum IX truncated (Fig. 30). Etymology. The species name maduraiensis refers to the locality, Madurai, Tamil Nadu where the new species was collected., Published as part of Muthukatturaja, Marimuthu & Balasubramanian, Chellaiah, 2021, A new species of Caenis Stephens, 1835 (Ephemeroptera: Caenidae) from Tamil Nadu, Southern India, pp. 366-372 in Zootaxa 4980 (2) on pages 367-371, DOI: 10.11646/zootaxa.4980.2.7, http://zenodo.org/record/4889226

Caenis americani Srinivasan, Sivaruban, Barathy, Malzacher & Isack sp. nov. (Figs 1���28) Materials Examined. Holotype (in alcohol): Female imago (Reg. No. ZSI���SRC/I/E/507), South India, Tamil Nadu, Dindigul district, Kodaikanal, Mangalamkombu, 10��30542���N & 77��67530���E; 1219 m; 16/II/2020, Pandiarajan Srinivasan & Rajasekaran Isack. Paratypes: 4 female imagoes (Reg. No. ZSI-SRC/I/E/508) and 7 female mature larvae (Reg. No. ZSI-SRC/I/E/509); 3 female imagoes (AMC /ZN/181) and 4 female mature larvae (AMC / ZN/182), same data as holotype. Mature larva (in alcohol) (Fig. 1): Body length: 4.7���4.9 mm; caudal filaments length: 2.6���3.2 mm; antennae length: 1.9 mm. Head: length 0.45 mm, width 1.20 mm. Middle ocellus larger than lateral ocelli. Hind margin without setae, setaceous type of antennae and presence of thin minute hairs on lateral sides just above each articulation of antennal segment. Pedicel with 4���5 simple setae on lateral margins (Fig. 3), genae not distinctly bulged. Mouthparts: Labrum (Fig. 4) length 0.17 mm, width 0.36 mm, 2.1 times broad as long, emargination with thick setae, anterior margin with row of long setae and scattered small stout setae on entire dorsal surface. Lingua of hypopharynx with very short spines on apical margin; apical margin emarginate (Fig. 5). Mandibles (Fig. 6, 7) each with single dorso-lateral row of long setae below incisors. Maxillary palp (Fig. 8) three-segmented and with ratio of 1: 0.8: 1.1; segment III covered with row of long stout setae near proximal end of inner margin. Labial palp (Fig. 9) three-segmented, segment I and II sub equal in length, segment III shorter and conical and 1/3 rdof length of segment II, segment I with row of setae on outer margin, segment II with row of setae on surface near outer margin and row of long simple setae on outer margin, segment III with 2 transverse row of stout setae near tip of distal margin. Thorax: Pronotum lateral margins denticulate; slightly concave with thin minute setae present on anterolateral and posterolateral margins; setae on anterolateral margins usually longer than those on posterolateral margins. Mesonotum distinctly bulged near anterolateral margins and numerous simple long setae present on lateral margins (Fig. 10), with denticulations. Legs: No coxal processes, with smooth margins. Foreleg (Fig. 11): lengths of femur: tibia: tarsus: claw viz., 0.86: 0.64: 0.51: 0.16 mm. Trochanter with row of thin simple setae on outer margin; femur with transverse row of 9���10 bifid bristles (Fig. 12) on �� of distal region; rows of simple setae on inner and outer margins; tibia with 3���4 bipinnate setae on dorsal margin, cluster of 7���8 long, robust setae on apex of distal region of ventral margin; tarsi with 2 stout spines at subapical proximal part of ventral margin, bipinnate setae on both margins and surface bifid bristles present; cluster of bipinnate setae at apex of distal region of tarsi; foreclaw, long and slender without denticles (Fig. 13). Midleg (Fig. 14): lengths of femur: tibia: tarsus: claw viz., 0.85: 0.58: 0.48: 0.20 mm. Trochanter similar to that of foreleg; femur with bifid bristles of various sizes scattered on surface (Fig. 15), row of thin, simple setae on half of ventral margin and entire dorsal margin; tibia with row of stout spines on ventral margin and on surface longitudinal row of bipinnate setae, numerous bipinnate and unipinnate setae scattered on surface and lateral margins; tarsi with row of spines directed medially and also 1���2 comb shaped bristles along with spines on ventral side; on dorsal side, numerous bipinnate and unipinnate setae scatteredly on lateral margins and surface; claw same as that of foreleg (Fig. 16). Hindleg (Fig. 17): lengths of femur: tibia: tarsus: claw viz., 0.91: 0.60: 0.51: 0.22 mm. Trochanter with 4���5 long, simple setae on surface; femur with unevenly distributed and more scattered simple setae on dorsal and ventral margins and bifid bristles scattered all over surface; tibia with cluster of spines on apical area of distal region, longitudinal row of bifid bristles on surface; tarsi with longitudinal row of 4���5 comb-shaped pinnate bristles along with longitudinal rows of spines on its ventral face and on dorsal side, 2 long and simple setae on distal region and 4 simple setae on proximal apex region; hindclaw long and slender, with row of very fine microdenticles (Fig. 18). Abdomen: Tergum I without posteromedian process; tergum II with posteromedian process with rounded tip at apex; posterolateral processes on terga I, II and III absent; terga IV���VI with size of posterolateral spines increasing posteriorly and reaching maximum on tergum VII; terga VIII���IX with small posterolateral spines compared to VII. Hind margins of terga VII and VIII with bristles (Fig. 19); terga IX and X with small denticles (Fig. 20). Gill 1 about half as long as gill 2. Gill 2 Y-ridge complete and well-developed (Fig. 21); dorsal surface with combination of bifid bristles and small spine-like processes (Fig. 22). Ventral row of microtrichia originates at some distance from base; laminar and slightly pinnate microtrichia (Fig. 23). Gills 3���6 with more numerous filaments (Fig. 24). Near hind margin of sternum IX, broad shagreen field of 4���5 rows of small denticles present. Hind margin of sternum IX slightly concave and emarginated with numerous cuts, and dense robust setae present medially, lateral margins with simple setae. Sternite IX strongly elongated posteriorly (Fig. 25). Color pattern: Head: ocelli black; vertex dark brownish with branch-like markings, ecdysial cleavage dark brownish, frons milk whitish color, genae light brown, mouth parts pale, venter of head whitish. Thorax: pronotum dark brown with one large and one small paramedian spot in each half of pronotum, lateral margins pale yellowish, mesonotum with median areas golden yellowish and lateral areas including lateral lobes thick brownish. Pro- and mesosternum light brown. Legs: Femora whitish with dark tinge in distal region, tibia and tarsus whitish with irregular blackish tinge, claw light reddish proximally. Abdomen: tergum I blackish brown; tergum II yellowish brown; tergum VII���X yellowish with dark brown tinges and tergum VII slightly paler than others; terga VII���IX each with 3 longitudinal pale stripes; middle one broader compared to others. Operculate gill thick brownish almost completely shaded with faint black tinge on outer half of Y-shaped ridge; minute black spots scattered on inner side; brownish tinges present on proximal and distal areas on inner side of Y-ridge. Caudal filaments pale yellowish and blackish at articulations; first articulation dark black. Sternum yellowish with light blackish tinge on lateral areas. Female imago (in alcohol) (Fig. 2): Body length: 3.2���3.5 mm; wing length: 3.0��� 3.2 mm; caudal filaments length: 2.1���2.3 mm. Wing venation: CuA1 forked with CuA2 immediately in distal part of CuA1-CuP vein (Fig. 26). Head: Ocelli large. Base of antenna distinctly dilated; pedicel three times length of scape. Thorax: Lateral margins of pronotum slightly concave and rounded, protruding anteriorly; broad mesonotum; prosternal ridges forming triangular structure, open anteriorly with straight lateral areas (Fig. 27). Abdomen: Absence of posteromedian finger-like processes on tergum II; lateral filaments short and apex of lateral filaments blunt and increasing in size from tergum III���VIII, reaching maximum size on tergum IX. Hind margin of sternum IX slightly emarginated medially; subanal plate clearly visible with fuzzy appearance and nearly straight (Fig. 28). Subgenital plate not clearly visible. Coloration: Head: yellow with thick blackish tinges, ocelli whitish, transverse medial line yellowish; venter of the head whitish, scape and pedicel whitish and antennae whitish with blackish tinge at articulations. Thorax: Pronotum dark brownish medially and yellow washed with brownish tinges laterally. Mesonotum yellowish and in distal part filled with black tinges and subapical area of median longitudinal ridge whitish; scutellum yellowish shaded with blackish. Prosternal triangular ridge reddish. Wing base and veins grayish; subcosta region blackish. Abdomen: tergum X whitish, terga III���IX whitish washed with black sparse pigmentation; terga I and II with irregular dark blackish tinges. Sternum VII���IX yellowish with black longitudinal stripes on lateral side; caudal filaments pale red. Etymology. The species name ��� americani ��� is made in honour of the institute The American College, Madurai, South India for their support of finding this new species. Diagnosis. The larva of C. americani sp. nov. can be distinguished from all other species of Caenis by the following combination of characters: i) distinct bulging margin of mesonotum (Fig. 10), ii) hind claw long and slender with a row of very fine microdenticles (Fig. 18) and iii) shape of sternite IX and its shagreen field (Fig. 25). Ecology. The larvae and imagoes of C. americani sp. nov. were collected in the stream of Mangalamkombu, Kodaikanal, Dindigul district (5���7 m wide, 1.1���1.3 cm depth). The water current was about 1.43 m /sec. The water temperature ranged between 20��C���22��C and pH 7.2���7.7. Substratum was high cobble and decayed leaf litter, with slow current. Molecular divergence. Due to limited molecular studies carried out on the Caenidae, especially in the Oriental region, our molecular comparison becomes restricted to a certain extent. From the COI based comparisons using K2P distance values, C. americani sp. nov. shows interspecific divergence within the range 0.189 ���0.246 (Table 2) with related species (based on NCBI database comparisons), the most similar species being C. horaria Linnaeus, 1758 and C. lactea Burmeister, 1839, with 0.189 and 0.199 divergence respectively. The K2P neighbor joining tree of COI reveals that C. americani sp. nov. forms a separate monophyletic clade (Fig. 29)., Published as part of Srinivasan, Pandiarajan, Sivaruban, T., Barathy, S., Malzacher, Peter & Isack, Rajasekaran, 2021, A new charismatic Caenis Stephens, 1835 (Ephemeroptera: Caenidae) from Southern India, pp. 105-116 in Zootaxa 4926 (1) on pages 106-112, DOI: 10.11646/zootaxa.4926.1.7, http://zenodo.org/record/4500708, {"references":["Linnaeus, C. (1758) Systema Naturae per regna tria Naturae, secundum classes, ordines, genera, species, cum Characteribus, Differentiis, Synonymis, Locis. 10 (1 - 3). Typis Ioannis Thomae, Vindobonae and Vienna, 1384 pp. https: // doi. org / 10.5962 / bhl. title. 542","Burmeister, H. (1839) Ephemerina. Handbuch der Entomologie, 2 (2), 788 - 804."]}

Caenis varicauda F.-J. Pictet, 1843 Ephemera sp. – Savigny, 1817: 194, pl. 2, figs 6-7. Caenis varicauda F.-J. Pictet, 1843 -1845: 281-282, pl. 43, fig. 5. Tricorythus varicauda. – Eaton, 1868: 82 (transfer). Accepted name: Tricorythus varicauda (F.-J. Pictet, 1843). Locus typicus: “… se trouve dans les partie supérieures de l’Egypte”. Type material: NMW; syntype, ♂ imago; KOTS 1 [= Kotschy leg.] / Pictet vidit / Typus [Ulmer’s handwriting]. – NMW; syntype, ♂ imago; KOTS 2 / Pictet vid. – NMW; syntype, ♂ imago; KOTS 3 / Pictet vid. Remarks: Theodor Kotschy (1813-1866) travelled the White and Blue Nile (Cairo to Torra, El Obeid, Torra, Karthum, Beni Shanqul) during 1836-1839. Material from this expedition was acquired by the NMW in 1839. In his redescriptions Ulmer (1916: 14; 1921: 248) quoted “vier Typen [four types]” misreading the collector’s acronym for “No. 21”. The fourth specimen, however, does not represent type material and actually originates from a series collected by Josef Franz Natterer (1819-1862) in “ Egypt ” [Karthoum], acquired by the NMW in 1858 and not seen by F.-J. Pictet. Beside this material, and as F.-J. Pictet mentioned “… et je la possède aussi dans ma collection”, four specimens are located in the MHNG. They were found under the name Caenis lactella Eaton, 1884 (a synonym of C. horaria) and all bear the same label: 620 48 Europe centr[ale] coll. Pictet. As no Tricorythus species has ever been reported from Europe, we can conclude that this is an example of the poor care the collection has suffered. These specimens fit the description given by F.- J. Pictet and may well constitute part of the original type series. This material is currently in ethanol. Eaton (1868) based his genus Tricorythus on Caenis varicauda F.-J. Pictet, 1843 which was recently redescribed by Kluge (2010)., Published as part of Sartori, Michel & Bauernfeind, Ernst, 2020, Mayfly types and additional material (Insecta: Ephemeroptera) examined by F. - J. Pictet and A. - E. Pictet, housed in the Museums of Natural History of Geneva and Vienna, pp. 315-339 in Revue suisse de Zoologie 127 (2) on pages 329-330, DOI: 10.35929/RSZ.0022, http://zenodo.org/record/5743794, {"references":["Pictet F. - J. 1843 - 1845. Histoire naturelle des Insectes Nevropteres. Famille des Ephemerines. J. Kessmann, Geneve, 300 pp. + 47 pl.","Savigny J. C. 1817. Description de l'Egypte, ou recueil des observations et des recherches qui ont ete faites en Egypte pendant l'Expedition de l'armee francaise, publiee par ordre du gouvernement. Histoire naturelle. Planches, vol. I. Imprimerie Royale, Paris, 2 pls.","Eaton A. E. 1868. An outline of re-arrangement of the genera of Ephemeridae. Entomologist's Monthly Magazine 5: 82 - 91.","Ulmer G. 1916. Ephemeropteren von Aquatorial-Afrika. Archiv fur Naturgeschichte (Abteilung A) 81 (7): 1 - 19.","Ulmer G. 1921. Uber einige Ephemeropteren-Typen alterer Autoren. Archiv fur Naturgeschichte (Abteilung A) 87 (6): 229 - 267.","Kluge N. J. 2010. Redescription of the taxon Tricorygnatha (Ephemeroptera, Tricorythus s. l.) based on new findings in Africa and Indonesia. Russian Entomological Journal 19 (2): 79 - 104."]}

Caenis luctuosa (Burmeister, 1839) Oxycypha luctuosa Burmeister, 1839: 797. Caenis luctuosa. – F.-J. Pictet, 1843 -1845: 283-284, pl. 45, fig. 3 (transfer). Material: NMW; 1 ♂, 1 ♀ (without data); Pictet vidit / Caenis luctuosa (Burmeister, 1839) / Malzacher det. 1983. Remarks: F.-J. Pictet did not mention that he received material from Kollar. The female specimen presumably had originally been placed under Caenis oophora (see above)., Published as part of Sartori, Michel & Bauernfeind, Ernst, 2020, Mayfly types and additional material (Insecta: Ephemeroptera) examined by F. - J. Pictet and A. - E. Pictet, housed in the Museums of Natural History of Geneva and Vienna, pp. 315-339 in Revue suisse de Zoologie 127 (2) on page 334, DOI: 10.35929/RSZ.0022, http://zenodo.org/record/5743794, {"references":["Burmeister H. 1839. Ephemerina. Handbuch der Entomologie 2 (2): 788 - 804.","Pictet F. - J. 1843 - 1845. Histoire naturelle des Insectes Nevropteres. Famille des Ephemerines. J. Kessmann, Geneve, 300 pp. + 47 pl.","Albarda H. 1878. Descriptions of three new European Ephemeridae. Entomologist Monthly Magazine 15: 128 - 130."]}

Caenis grisea F.-J. Pictet, 1843 Caenis grisea F.-J. Pictet, 1843 -1845: 278-279, pl. 45, figs 1-2. Caenis macrura (Stephens, 1836). – Eaton, 1871: 93 (synonymization). – Malzacher, 1986: 15. Caenis halterata (Fabricius, 1777). – Eaton, 1885: 145 (synonymization). Accepted name: Caenis macrura (Stephens, 1836). Locus typicus: “… dans un petit marais situé au pied du mont Salève”. Type material: Syntypes (male imago and subimago), not traced and most probably lost. Remarks: In the MHNG there is one specimen (female subimago) which bears the name Caenis halterata Fabr. and originates from Burgdorf (coll. Meyer-Dür). This specimen belongs to Caenis luctuosa (Burmeister, 1839). Without any new available data, we accept the synonymy proposed by Eaton (1871) and followed by Malzacher (1986), but in our opinion C. grisea could also be considered a junior subjective synonym of C. luctuosa (Burmeister, 1839)., Published as part of Sartori, Michel & Bauernfeind, Ernst, 2020, Mayfly types and additional material (Insecta: Ephemeroptera) examined by F. - J. Pictet and A. - E. Pictet, housed in the Museums of Natural History of Geneva and Vienna, pp. 315-339 in Revue suisse de Zoologie 127 (2) on page 329, DOI: 10.35929/RSZ.0022, http://zenodo.org/record/5743794, {"references":["Pictet F. - J. 1843 - 1845. Histoire naturelle des Insectes Nevropteres. Famille des Ephemerines. J. Kessmann, Geneve, 300 pp. + 47 pl.","Stephens J. F. 1836. Family III. - Ephemeridae, Leach. Illustrations of British Entomology, Mandibulata 6: 54 - 70, pl. 29.","Eaton A. E. 1871. A monograph of the Ephemeridae. Transactions of the Entomological Society of London 1871: 1 - 164.","Malzacher P. 1986. Diagnostik, Verbreitung und Biologie der europaischen Caenis - Arten (Ephemeroptera: Caenidae). Stuttgarter Beitrage zur Naturkunde (Serie A, Biologie) 387: 1 - 41.","Fabricius J. C. 1777. Genera insectorum eorumque characteres naturales secundum numerum, figuram, situm et proportionem omnium partium oris adiecta mantissa specierum nuper detectarum. M. F. Bartschii, Chilonii (= Kiel), i-xiv + 310 pp + 16 pl.","Burmeister H. 1839. Ephemerina. Handbuch der Entomologie 2 (2): 788 - 804."]}

Caenis oophora F.-J. Pictet, 1843 Caenis oophora F.-J. Pictet, 1843 -1845: 284-285, pl. 45, fig. 4. Caenis macrura (Stephens, 1836). – Ulmer, 1921: 248 (synonymization). Accepted name: Caenis oophora F.-J. Pictet, 1843 nom. dub. Locus typicus: “… originaire de Sardaigne ”. Type material: NMW; holotype [by monotypy], ♀ [subimago]; Caenis macrura Stephens, female subimago / Dhl. a. c. [= Dahl, alte collection?] / Pictet vidit. Remarks: The type specimen, denoted “femelle imago” by F.-J. Pictet, corresponds with his description and illustration. It had presumably been collected by Georg Dahl (1769-1832), naturalist and dealer in natural history specimens, who collected in Sardinia and whose respective material was acquired by the NMW in 1826. Ulmer (1921: 248) mentioned two female specimens with F.-J. Pictet’s label, originating from Sardinia, but Pictet (1843) expressly mentionned that he examined only one specimen: “L’individu que j’ai eu à ma disposition...”. The second specimen, with protruding eggs and labelled “Pictet vidit” (but without collector’s label or locality) which corresponds with Ulmer’s description, was doubtfully identified as “ C.? luctuosa (Burm.) det. Malzacher 1983”. Another female specimen, labelled “ C. oophora Pict. Sardinien (Mann) [probably Kollar’s handwriting] / Pictet vidit” does not correspond with F.-J. Pictet’s description and was probably subsequently identified by Kollar, but it had not been examined by F.-J. Pictet. It had either been obtained from or collected by Josef Johann Mann (1804-1889), who travelled Corsica in 1855 and Sicily in 1858 (Rogenhofer, 1889). In the light of this poor and contradictory evidence, the name C. oophora Pictet, 1843 is probably best considered a nomen dubium., Published as part of Sartori, Michel & Bauernfeind, Ernst, 2020, Mayfly types and additional material (Insecta: Ephemeroptera) examined by F. - J. Pictet and A. - E. Pictet, housed in the Museums of Natural History of Geneva and Vienna, pp. 315-339 in Revue suisse de Zoologie 127 (2) on page 330, DOI: 10.35929/RSZ.0022, http://zenodo.org/record/5743794, {"references":["Pictet F. - J. 1843 - 1845. Histoire naturelle des Insectes Nevropteres. Famille des Ephemerines. J. Kessmann, Geneve, 300 pp. + 47 pl.","Stephens J. F. 1836. Family III. - Ephemeridae, Leach. Illustrations of British Entomology, Mandibulata 6: 54 - 70, pl. 29.","Ulmer G. 1921. Uber einige Ephemeropteren-Typen alterer Autoren. Archiv fur Naturgeschichte (Abteilung A) 87 (6): 229 - 267.","Rogenhofer A. 1889. Josef Mann. Ein Nachruf. Wiener Entomologische Zeitung 8 (7): 241 - 245."]}

Caenis horaria (Linnaeus, 1758) Caenis lactea. – F.-J. Pictet, 1843 -1845: 276-277, pl. 43, figs 1-4, pl. 44 (nec Oxycypha lactea Burmeister, 1839; misidentification). Caenis horaria (Linnaeus, 1758). – Jacob, 1974: 94. Material: NMW; 2 ♂ imagines, 1 ♂ subimago; coll. Nat. Mus. Wien [without locality data]. Remarks: F.-J. Pictet did not mention that he received material from Kollar, but in the NMW three specimens presumably had originally been deposited under the name Caenis lactea Pictet and identified by Malzacher as: Caenis horaria (Linnaeus, 1758) / Malzacher det. 1983., Published as part of Sartori, Michel & Bauernfeind, Ernst, 2020, Mayfly types and additional material (Insecta: Ephemeroptera) examined by F. - J. Pictet and A. - E. Pictet, housed in the Museums of Natural History of Geneva and Vienna, pp. 315-339 in Revue suisse de Zoologie 127 (2) on page 334, DOI: 10.35929/RSZ.0022, http://zenodo.org/record/5743794, {"references":["Linnaeus C. 1758. Systema Naturae, ed. X. L. Salvii, Holmiae, 824 pp.","Pictet F. - J. 1843 - 1845. Histoire naturelle des Insectes Nevropteres. Famille des Ephemerines. J. Kessmann, Geneve, 300 pp. + 47 pl.","Burmeister H. 1839. Ephemerina. Handbuch der Entomologie 2 (2): 788 - 804.","Jacob U. 1974. Zur Kenntnis zweier Oxycypha - Arten Hermann Burmeisters (Ephemeroptera, Caenidae). Reichenbachia 15 (14): 93 - 97."]}

A.33. Caenis cubensis Malzacher, Naranjo, González-Lazo and Kluge, 2007 Figures 19, 61. Caenis cubensis Malzacher, Naranjo, González-Lazo and Kluge 2007:226 (male and female imagos, nymph, egg). Holotype. Male imago, Province Santiago de Cuba, Río Guamá (Sierra Maestra), 4-IV-1989, N. Kluge. Originally described by Malzacher et al. (2007) from multiple localities in all regions of Cuba, this is the only species of Caenis on the island. Ecology. Caenis cubensis is found in a wide range of altitudes up to 900 m, but it has been collected most frequently below 500 m and less frequently between 750 and 900 m, especially in Bayamesa National Park of the Sierra Maestra. Specimens have been collected in contaminated rivers, lakes and even a swimming pool (Malzacher et al. 2007). Nymphs with black wing pads have been collected throughout the year. Geographic distribution. Present in all four geographic regions of Cuba. Malzacher et al. (2007) stated that this mayfly is the most widespread of any species in the country and is possibly the most common species (Fig. 19). Paratypes (Appendix 2) are listed from nine provinces and the Isla de la Juventud., Published as part of L, Carlos Naranjo, Peters, Janice G., del, Pedro López & Castillo, 2019, Ephemeroptera (Insecta) in Cuba, pp. 1-52 in Insecta Mundi 2019 (736) on page 19, DOI: 10.5281/zenodo.5170691, {"references":["Malzacher, P., C. Naranjo, D. Gonzalez-Lazo, and N. J. Kluge. 2007. Caenis cubensis, a new species of mayflies from Cuba (Ephemeroptera: Caenidae). Aquatic Insects 29: 225 - 233."]}

Streams in the Mongolian Altai Mountains are mostly fed from glaciers and are extreme conditions for mayflies because of high elevation, low temperatures and low annual precipitation. Previous information about mayflies of Western Mongolia is scarce, but with this study a total of 38 species belonging to 26 genera and subgenera and 8 families of mayflies has been recorded in the Mongolian Altai region. Study material was entirely imagos and collected from 78 sites during expeditions led by the Mongolian Aquatic Insect Survey in 2008, 2009 and 2010. Raptobaetopus tenellus, Caenis luctuosa and Caenis rivulorum are recorded as new to the fauna of Mongolia, and there are new distribution records for Ameletus montanus, Baetis (Acentrella) lapponica, Baetis sibiricus, Baetis (Labiobaetis) attrebatinus, Centroptilum luteolum, Procloeon pennulatum, Ephemerella aurivillii, Serratella setigera, Ephemera sachalinensis, Ecdyonurus (Afronurus) abracadabrus, Cinygmula kurenzovi, Ecdyonurus (Afghanurus) vicinus and Epeorus (Belovius) pellucidus from the Mongolian Altai region. Baetis vernus and Ephemerella aurivillii are the most frequently encountered species in this region.

Caenis cuniana Froehlich, 1969 (Figs. 1, 4���5) Caenis sp. Demoulin 1955: 4 (nymph) Caenis cuniana Froehlich, 1969: 104 (female imago, nymph); Hubbard, 1982a: 261; Da-Silva, 1993: 413 (male imago); Salles et al., 2010: 304 (nymph); Shimano et al., 2011: 245 (nymph); Lima et al., 2015: 3 (nymph). Caenis? cuniana Malzacher, 1986: 94 (nymph). Egg. Length: 94���126 ��m; width: 77���91 ��m. Coloration light yellow. Oval shaped with length 1.2���1.4 maximum width. Chorion surface smooth with polygonal imprints of follicle cells as in Fig. 4. One coiled polar cap with about ten terminal knobs (Fig. 5), and positioned around the main axis. Micropyle funnel-shaped, very short, with a small sperm guide (Fig. 4). Distribution. Brazil: States of Esp��rito Santo, Mato Grosso, Par��, Rio de Janeiro and S��o Paulo. New record: Roraima State. Material examined. Eight imagos (five females and three males), Brazil, Roraima State, Boa Vista county, Rio Cauam��, Campus Cauam�� da Universidade Federal de Roraima, 2��51���46 N/ 60��42���53��� W, 09.vii.2016; Boldrini, R. coll. One female imago (reared) and two nymphs, Brazil, Roraima State, Cant�� county, Serra Grande II, 2��32���N / 60��46���W; Boldrini, R. and Salles, F.F. cols. Comments. Caenis cuniana has been described from imagos of both sexes, nymphs and eggs (Froehlich 1969; Da-Silva 1993) and is characterized by the male genitalia with strong, sclerotized, and apically pointed forceps, and nymphs with large denticles on fore and middle tarsal claws. In the original description, the eggs were only superficially described by Froehlich (1969) without pictures or SEM images. Froehlich (1969) reported polar cap either at one or at both poles. However, in our material we observe only single-capped eggs (Fig. 4). This mix of single- and double-capped eggs also exist in the North American species C. anceps Traver, 1935 and C. hilaris (Say, 1839). This record of C. cuniana is the second from the Amazon River Basin (Northern Brazil) with the first by Malzacher (1986)., Published as part of Lima, Lucas R. C. & Boldrini, Rafael, 2017, New distributional records and life stage description of Caenis species (Ephemeroptera: Caenidae) from Brazil, pp. 285-292 in Zootaxa 4276 (2) on page 286, DOI: 10.11646/zootaxa.4276.2.10, http://zenodo.org/record/806137, {"references":["Froehlich, C. G. (1969) Caenis cuniana sp. n., a parthenogenetic mayfly. Beitrage zur Neotropischen Fauna, 6 (2), 103 - 108.","Demoulin, G. (1955) Une mission biologique belge au Bresil. Ephemeropteres. Bulletin de l'Institut Royal des Sciences Naturelles de Belgique Entomologie, 31 (20), 1 - 32.","Hubbard, M. D. (1982) Catalogo abreviado de Ephemeroptera da America do Sul. Papeis Avulsos de Zoologia, 34, 257 - 282.","Da-Silva, E. R. (1993) Descricao do imago macho de Caenis cuniana Froehlich, com notas biologicas (Ephemeroptera, Caenidae). Revista Brasileira de Zoologia, 10 (3), 413 - 416.","Salles, F. F., Nascimento, J. M. C., Massariol, F. C., Angeli, K. B., Silva, P. B., Rudio, J. A. & Boldrini, R. (2010) Primeiro levantamento da fauna de Ephemeroptera (Insecta) do Espirito Santo, sudeste do Brasil. Biota Neotropica, 10 (1), 293 - 307. Avaliable from: http: // www. biotaneotropica. org. br / v 10 n 1 / pt / abstract? inventory + bn 02610012010 (Accessed 9 Jun. 2017)","Shimano, Y., Salles, F. F. & Cabette, H. S. R. (2011) Ephemeroptera (Insecta) from east of Mato Grosso state, Brazil. Biota Neotropica, 11 (4), 239 - 253.","Lima, L. R. C., Salles, F. F. & Pinheiro, U. (2015) New records of mayflies (Ephemeroptera: Insecta) from Pernambuco state, Northeastern Brazil. Check List 11 (3), 1 - 7.","Malzacher, P. (1986) Caenidae aus dem Amazonasgebiet (Insecta, Ephemeroptera). Spixiana, 9, 83 - 103."]}

Caenis teipunensis Molineri, Grillet, Nieto, Dom��nguez & Guerrero, 2011 (Fig. 3) Caenis teipunensis Molineri et al., 2011: 40 (adults). Distribution. Venezuela: Bol��var State. New record: Brazil: Roraima State. Material examined. Nine male imagos, Brazil, Roraima State, Amajari county, Serra do Tepequ��m, Pousada da PSJ, 3��46���54��� N / 61��43���31���W, 27.iii.2016, Takiya, D.M. coll. One male imago, Brazil, Roraima State, Amajari county, Serra do Tepequ��m, Trilha do Paiva, 3��45���59.59��� N / 61��44���40.67���W, 30.iii.2016, Barroso, P.C.S. and TaKiya, D.M. cols. One male imago, Brazil, Roraima, Pacaraima county, pista de pouso, 3�� PEF (light trap), 4��29���38��� N, 61��10���06��� W, 10.vi.2016; Boldrini, R. and Barroso, P.C.S. cols. Comments. Caenis teipunensis is closely related to C. fittkaui Malzacher, 1986, another species in which the male imago present the apically pointed forceps. It is easily distinguished from C. fittkaui which has short apophyses compared with extremely long apophyses in C. teipunensis as in the figures provided by Molineri et al. (2011)., Published as part of Lima, Lucas R. C. & Boldrini, Rafael, 2017, New distributional records and life stage description of Caenis species (Ephemeroptera: Caenidae) from Brazil, pp. 285-292 in Zootaxa 4276 (2) on pages 287-288, DOI: 10.11646/zootaxa.4276.2.10, http://zenodo.org/record/806137, {"references":["Molineri, C., Grillet, M. - E., Nieto, C., Dominguez, E. & Guerrero, E. (2011) New species and records for the mayfly families Caenidae, Leptohyphidae and Coryphoridae (Ephemeroptera, Pannota) from Venezuelan Guayana's Uplands Zootaxa, 2750, 39 - 50.","Malzacher, P. (1986) Caenidae aus dem Amazonasgebiet (Insecta, Ephemeroptera). Spixiana, 9, 83 - 103."]}

Caenis elidioi Lima, Molineri, Pinheiro & Salles, 2016 (Fig. 2) Caenis sp. Angeli et al., 2015: 200 (adults); Lima et al., 2016b: 215 (adults and nymphs). Caenis elidioi Lima et al., 2016a: 117 (adults, nymph and eggs). Distribution. Brazil: States of Bahia, Cear��, Esp��rito Santo, Maranh��o, Mato Grosso, Minas Gerais, Para��ba, and Pernambuco. New record: Roraima State. Material examined. Seven males imagos, Brazil, Roraima State, Amajari, Esta����o Ecol��gica de Marac��, 11��� 19.xi.2007, Pes, A.M.O., Neiss, U.G. and Albino, J. cols. Comments. Caenis elidioi, recently described from all stages by Lima et al. (2016a), is another species from the lineage with strong and apically pointed forceps. C. elidioi can be characterized, among other characters by the presence of forceps pointed, sharpening abruptly and forming a long tip at the apex, and penes dorsally and laterally protruding as Figs. 8���9 in Lima et al. (2016a). This species seems to be widespread in Brazil and its record here represent the first in the Amazon River Basin., Published as part of Lima, Lucas R. C. & Boldrini, Rafael, 2017, New distributional records and life stage description of Caenis species (Ephemeroptera: Caenidae) from Brazil, pp. 285-292 in Zootaxa 4276 (2) on page 286, DOI: 10.11646/zootaxa.4276.2.10, http://zenodo.org/record/806137, {"references":["Lima, L. R. C., Molineri, C., Pinheiro, U. & Salles, F. F. (2016 a) Two new species of Caenis Stephens, 1835 (Ephemeroptera: Caenidae) from South America. Zootaxa, 4170 (1), 114 - 124. http: // dx. doi. org / 10.11646 / zootaxa. 4170.1.5","Angeli, K. B., Rozario, E. M. & Salles, F. F. (2015) Checklist of Ephemeroptera (Insecta) from Sao Mateus River Basin, Espirito Santo, Brazil. Revista Brasileira de Entomologia, 59, 197 - 204.","Lima, L. R. C., Knapp, W. & Docio, L. (2016 b) New records of mayflies (Insecta: Ephemeroptera) from Bahia State, Northeastern Brazil. Entomotropica, 31 (25), 212 - 220."]}

Caenis elidioi sp. nov. (Figures 6���33) Caenis sp., Angeli et al. 2015: 200 (adults); Lima et al. 2016: 215 (adults and nymphs). Diagnosis. This species can be characterized by the following combination of characters. In the imagos: 1) body length of male 2.1���3.3 mm, of female 3.5���4.3 mm; 2) base of antennal flagellum not dilated; 3) forceps pointed, sharpening abruptly and forming a long tip at the apex (Figs. 8, 10���13); 4) styliger plate with posterior margin straight to slightly subtriangular (Fig. 10); 5) penes dorsally and laterally protruding (Figs. 9���10). In the nymph: 1) body length of male 2.8���3.3 mm, of female 3.8���4.5 mm; 2) anterolateral margins of pronotum rounded; 3) coxal processes of middle and hind legs well-developed and semicircular, with smooth margins (Fig. 25); 4) tarsal claws I and II without denticles, tarsal claw III with ca. 20 small denticles (Figs. 31���33); 5) hind margin of the ninth sternite rounded (Fig. 19); 6) posterolateral projections on abdominal segments V���VIII short and pointed; 7) dorsal surface of operculate gills without short and strong microspines (Fig. 17). Eggs: 1) two polar caps of coiled-rope type (Fig. 14); 2) oval shaped, length 1.00���1.16 maximum width. Description. Male imago. Body length: 2.1���3.3 mm; forewing length: 2.0��� 2.4 mm; foreleg length: 1.8���2.2 mm; hind leg length: 1.1���1.3 mm; cercus length: 7.1���7.4 mm. Ratios. Leg: body size 1.17���1.38 length of foreleg; foreleg 1.59���1.83 the length of hind leg; 1st segment of foretarsus length: 2nd: 3rd: 4th: 5th = 1:4.6���5.0:2.0���2.5:1.4���1.8:1.2���1.5. Genitalia: styliger plate length 0.54���0.62 width; forceps length 8.3��� 9.6 its width at distance from base; distance between extreme lateral points of forceps bases to distance of forceps length = 1.40���1.64. Coloration. Head: whitish shaded with black dorsally, except for pale transverse medial line; venter of head whitish. Antenna: scape and pedicel whitish, shaded with gray; flagellum hyaline, shaded with black at base. Thorax. Prothorax whitish, shaded with black dorsally, with two spots near middle; prosternum whitish, shaded with black near base of legs. Meso- and metanotum light brown, shaded with black on carinae; pleurae and sterna brown, shaded with black. Wing membrane hyaline, veins translucent except C, Sc and Rs grayish. Legs whitish with all coxae, femora and foretibiae shaded with black; subapical blackish marks present on all femora, median marks on middle and hind tibiae. Abdomen. Whitish with black bands dorsally, paler laterally (Fig. 6). Terga I���II and VII���IX darker laterally. Sterna whitish, except IX���X blackish. Pleura with tracheae strongly pigmented. Genitalia. Sternum IX with chitinous lateral structures strongly colored. Forceps dark brown. Penes whitish, with ventral, semi-circular dark brown sclerite (Fig. 8). Caudal filaments whitish translucent. Morphology. Antenna: Base of flagellum not dilated. Thorax. Pronotum with lateral margins straight, not protruding; prosternal longitudinal ridges forming triangleshaped structure, anteriorly open and laterally with straight margins (Fig. 7). Abdomen. Lateral filaments present on terga VII���VIII, very short; finger-like process on tergum II lacking. Genitalia. Styliger plate subrectangular with apex slightly subtriangular (some specimens with small tubercles medially on posterior margin); central sclerite elongate dome shaped; apophyses short, triangular and pointed; lateral sclerites with broad base, more or less curved, not extended forward to central sclerite; basolateral sclerites divergent, laying distant from the lateral sclerites (Fig. 8). Forceps pointed, located close to lateral margins of styliger plate, sharpening abruptly, forming long tip at apex; main axis with small denticles on ventral surface of inner margin (Figs. 10���13). Penes dorsally and laterally protruding (swollen in some specimens), with tubercles (Figs. 8���9), and with apical incision. Female imago. Body length, 3.5���4.3 mm; forewing length, 2.4���2.6 mm; foreleg length, 1.4���1.8 mm; cercus length, 2.1���2.6 mm. Same coloration as in male except mesokatepisternum dark brown, with rest of mesopleural sclerites paler. Lateral filaments present on terga VII���IX, very short. Abdominal sternum IX rounded, not projected. Egg. Length: 95���105��m; width: 90���95��m. Coloration light yellow. Oval shaped with length 1.00���1.16 maximum width. Chorion finely punctured. Two coiled-rope type polar caps with about ten terminal knobs and more-or-less eccentric position in relation to main axis (Fig. 14). Micropyle funnel-shaped, narrow and long, without sperm guide (Fig. 15). Nymph (Fig. 16). Length of male: body, 2.8���3.3 mm; cercus, 2.5���2.9 mm. Length of female: body, 3.8���4.5 mm; cercus, 3.7���4.2 mm. Ratios. Mouthparts: width of maxillary palp segment I 1.6���2.0 width of segment II; length of maxillary palp segment I 1.3���1.8 length of segment II; length of maxillary palp segment I 0.8���1.0 length of segment III. Leg: length of forefemur 2.8���3.6 its maximum width. Coloration. Head: light brown; occiput and mouthparts paler, grayish markings forming irregular net on occiput; also shaded gray behind eyes. Antenna: scape and pedicel light brown, flagellum hyaline. Thorax. Nota brownish with black sutures. Pronotum with translucent anterolateral corners, shaded with black on anterior margin and lateral zones; with blackish paramedian dots and median elongated marks. Mesonotum with blackish macula anterior to wingbud bases, with pair of medial blackish lines. Legs yellowish, with blackish marks present on subapical zones of femora and basally on tibiae. Thoracic sterna paler. Abdomen. Terga brownish; segments I���II with grayish band on medial area; segments VIII���X, paler medially and darker laterally. Operculate gills translucent yellowish, almost completely shaded with black and apically with 3 or 4 blackish spots. Abdominal sterna much paler, with only small grayish sublateral marks. Caudal filaments yellowish. Morphology. Head: hind margin without setae. Mouthparts: lateral margins of labrum rounded, with long subapical setae on dorsal surface (Fig. 20); mandibles with dorso-lateral row of long setae (Fig. 22); lingua of hypopharynx with fore margin almost straight (Fig. 23). Thorax. Pronotum with anterolateral margins rounded and directed anteriorly; lateral margins denticulate. Legs: coxal projections well-developed and semicircular, with smooth margins (Fig. 25). Ventral and dorsal margins of fore femora with short robust setae (Fig. 26); middle and hind femora each with long robust setae on dorsal margin (Figs. 27���28); transverse rows of spatulate setae of forefemora reduced, only with 3 or 4 setae (Fig. 26). Foretarsus with one marginal row of simple pointed setae (Fig. 31), middle tarsus with one marginal row of serrated setae, and hind tarsus with two rows of setae (Fig. 33): one simple and one serrated (Fig. 28, 33). Claws: tarsal claws I and II without denticles (Figs. 31���32); tarsal claw III with ca. 20 minute denticles (Fig. 33). Abdomen. Tergum II with small projection, wide at base and posteriorly curved. Operculate gills with microtrichia from the submarginal ventral row elongated and apically frayed (Fig. 18); Y-ridge complete and welldeveloped; dorsal surface smooth with long, simple setae (Fig. 17). Posterolateral projections on abdominal segments V���VIII short and pointed. Sternum IX with hind margin rounded, laterally denticulate and posteriorly with long simple setae (Fig. 19). Life cycle association: The association between male imago and nymphs was made by rearing. Distribution. Brazil: states of Bahia, Cear�� State, Esp��rito Santo, Maranh��o, Mato Grosso, Minas Gerais, Para��ba, and Pernambuco. Etymology. This species is named to honor Elidiomar Ribeiro Da-Silva, known as ���Elidio���, in recognition of his contributions to the intellectual development of authors FFS and UP, with regards to taxonomy. Material examined. Holotype: One male imago (reared), Brazil, Bahia State, Barreiras, Vau da Boa Esperan��a, C��rrego de Primeira Ordem Ponto 2, S12��12'21.40", W45��13'27.28", 16.iii. 2014, 556m, Lima, LRC, Knapp, W. cols. (CZNC 6776). Paratypes: Five nymphs, Brazil, Pernambuco State, Camaragibe, Rio Besouro, Estrada do Borralho, KM 0 7, PE-027, S7��59'06.4", W35��00'13.9", 16.vii.2009, 66m, Lima, LRC. col. (CEUFPE 350224). Three female imagos (reared), Recife, riacho da UFRPE, S08��00'57.4", W34��56'46.4", 22.iii.2013, 48m, Lima, LRC col. (CZNC 6773, 6775 and 6777); same data as preceding except one female imago (reared) (CZNC 6775). One nymph, Brazil, Bahia State, Barreiras, Vau da Boa Esperan��a, C��rrego de Primeira Ordem Ponto 1, S12��12'18.26", W45��13'30.09", 14.xii. 2013, 548m, Knapp, W. col (CZNC 6779); same data as preceding except, 11 male imagos, 16.iii.2014 (CZNC 6780); same data as preceding except, three female imagos (CZNC 6781); 55 males and 15 females (light trap), Brazil, Pernambuco State, Tamandar, Riacho Mamucabas Ponto 2, pr��ximo sede da Rebio Saltinho, S08��43'52.7", W35��10'24.8", 28.iii.2014, 38m, Lima, LRC col. (IBN); same data as preceding except, 92 male imagos, 17.iv.2014 (CZNC 6782); same data as preceding except, 63 females same data except (CZNC 6778). Additional material. Four male imagos, Brazil, Cear�� State, Ubajara, Serra do Ibiapaba, Parque Nacional de Ubajara, S03��50'40.8", W40��54'35", 23.x. 2011, 858m, Silva-Neto, A; Xavier, M.; Lima, E. cols (CEUFPE). Four male imagos (Pennsylvania light trap), Brazil, Esp��rito Santo, Nova Ven��cia, entrada da cidade, Casa da Dona Ana e Seu Adalto, Rio Cricar, S18��42'54.91", W40��22'33.33", 26-27.vii.2012, Rozario, Gon��alves and Angeli cols. (CZNC 4477). One male imago (Pennsylvania light trap), Brazil, Esp��rito Santo, Nova Ven��cia, Santa Rita do Pip Nuck, Casa do Sr Pupim, Rio Cricar, S18��39'51.4'', W40��30'44.9'', 18-19.ii.2013, Rozario, Gon��alves and Angeli cols. (CZNC 5962). One male imago (Pennsylvania light trap), Brazil, Esp��rito Santo, S��o Mateus, Propriedade do Sr. F��bio Gama, Rio Cotax, S18��37'41.1", W40��6'41.6", 05-06.ii.2013, Rozario, Gon��alves and Angeli cols. (CZNC 6004). 182 male imagos, Brazil, Maranh��o State, Caxias, Aldeias Altas, Riacho Limpeza, S4��38��� 26.35, W43��26��� 37.42, 21.vii.2015, Sousa, D.E. col (CZMA). Three female imagos and 5 male imagos (light trap) Brazil, Mato Grosso State, Nova Xavantina, Bacaba, nascente, S52��21��� 48, W14��43��� 3, 06.vii.2011, Cabette, HRS. col. (UNEMAT 9563). Two female imagos and one male imago, Brazil, Minas Gerais State, Serra do Cip��, Parque Nacional da Serra do Cip, C��rrego das Pedras, S19��22���17'', W43��36���02.2'', 02���03.ii.2015, Salles, FF. col. (CZNC 6575). Two male imagos Brazil, Para��ba State, Mamanguape, Rebio Guaribas, Rio Cabe��a de Boi, 29.vii.2007 (CEUFPE). 18 females imagos, Brazil, Pernambuco State, Recife, caminho para o A��ude do Prata, Parque Dois Irm��os, S8��00'28.5", W34��56'54.3", 22.viii.2009, 31m, Lima, LRC col. (CEUFPE 350219); three females imagos (reared), same data as preceding except 12.ix.2009 (CEUFPE 350225); one male imago (reared), same data as preceding except 17.iii.2010 (CE-UFPE 350234). Three female imagos (reared), Brazil, Pernambuco State, Recife, riacho da UFRPE, S08��00'57.4", W34��56'46.4", 06.iv.2010, 48m, Lima, LRC col. (CEUFPE 350205); three nymphs, same data as preceding except 17.iv.2010 (CEUFPE 350216); four male imagos, same data as preceding except 18.xii.2012 (CZNC 6772); same data as preceding except, one nymph and one male imago, 22.iii.2013 (CZNC 6771, 6774); one nymph, four males and 11 females imagos (IBN 674CM and IBN 675CM) same data except 14.ii.2014 (IBN). Five nymphs, Brazil, Pernambuco State, Igarassu, Riacho Jacoc, Ref��gio Charles Darwin, S07��48'57.5", W34��57'19.1", 22.iii.2010, 37m, Lima, LRC col. (CEUFPE 350227). One nymph, Pernambuco State, Goiana, A��ude Santa Tereza, S07��35'33.2", W34��59'32.8", 12.xi.2011, 35m, Lima, LRC, Souza, WRM cols. (CEUFPE 350206). Two nymphs, Brazil, Pernambuco State, S��o Jo��o, Riacho da Barragem Inhumas, S08��58'17.3", W36��21'48.5", 13.ii. 2012, 686m, Lima, LRC, Souza, WRM cols (CEUFPE 350226). Six males and two females imagos, Brazil, Pernambuco State, Amaraji, Barragem Jaguarana, S08��21'01.6", W35��24'27.7", 05.xii. 2012, 265m, Lima, LRC col. (CEUFPE). One female imago (reared), Brazil, Pernambuco State, Rio Formoso, Riacho Gameleira, Rebio Saltinho, S08��43'12.3", W35��10'32.9", 22.xi.2012, 47m, Lima LRC, Souza, WRM cols. (CEUFPE 350231)., Published as part of Lima, Lucas R. C., Molineri, Carlos, Pinheiro, Ulisses & Salles, Frederico F., 2016, Two new species of Caenis Stephens, 1835 (Ephemeroptera: Caenidae) from South America, pp. 114-124 in Zootaxa 4170 (1) on pages 117-122, DOI: 10.11646/zootaxa.4170.1.5, http://zenodo.org/record/258640, {"references":["Angeli, K. B., Rozario, E. M. & Salles, F. F. (2015) Checklist of Ephemeroptera (Insecta) from Sao Mateus River Basin, Espirito Santo, Brazil. Revista Brasileira de Entomologia, 59, 197 - 204. http: // dx. doi. org / 10.1016 / j. rbe. 2015.06.004","Lima, L., Knapp, W. & Docio, L. (2016) New records of mayflies (Insecta: Ephemeroptera) from Bahia State, Northeastern Brazil. Entomotropica, 31 (25), 212 - 220."]}

Caenis teipunensis sp. nov. (Figs. 1–6) Material. Venezuela, Estado Bolívar: 15 3 (slide 518) and 1 Ƥ imagos from Kavanayén stream, N 5 ° 37 ' 27 " - W 61 ° 44 ' 37 ", 1355 m, 21 /XI/ 2005, EG, AMO, CA and MEG cols.; 23 3 (slides 510, 516, 517) and 3 Ƥ imagos from Kako-Parú stream, N 4 ° 54 ' 0" – W 61 ° 5 ' 25 ", 913 m, 28 /VI/ 2007, EG, AMO, CA and MEG cols. Holotype 3 imago, allotype Ƥ imago and 10 paratype 3 imagos at MLBV; 5 paratype 3 imagos at INPA; rest in IML. Male imago. Length (mm): body, 3.0– 3.6; forewings, 2.5–2.9; foreleg (from base of trochanter to apex of claw), 1.8–2.3; caudal filaments, 6.5 –9.0. General coloration yellowish light brown (Fig. 1). Head yellowish white shaded with gray widely except on a transversal pale band between anterior part of lateral ocelli; venter of head pale. Antennae: scape yellowish gray, pedicel yellowish translucent, flagellum hyaline. Thorax. Prothorax yellowish translucent shaded with gray dorsally, darker on a pair of submedian spots; presternal triangle anteriorly pointed (Fig. 2). Mesonotum and metanotum yellowish orange shaded with gray on carinae, pleurae and sterna paler. Wings hyaline, veins translucent except C, Sc and Rs grayish. Legs. All coxae, fore femora and base of fore tibiae yellowish; rest of foreleg and middle and hind legs whitish; median and subapical gray marks present on all femora, submedian gray mark also on middle and hind tibiae. Abdomen. Segments 1–8 whitish-translucent, 9–10 yellowish, without lateral or dorsal filaments; all terga shaded widely with gray, darker on terga 1–2 and lateral spots of terga 1–9; sterna translucent white with light gray marks on lateral margins of sterna 8–9. Genitalia (Figs. 3, 5– 6) with whitish membranes and yellowish sclerites; forceps orangeish, long and slender, apically pointed and sclerotized, generally sharpening abruptly at the apex, few setae and small tubercles present but variable (Figs. 6 a–f); penes (Figs. 3, 5) whitish with a yellowish V-shaped mark, ventral surface with small tubercles and shallow groove, lobes of the penes rounded laterally; styliger plate with elongated and oval central sclerite, apophyses strongly developed, wide and long (Figs. 3, 5). Caudal filaments whitish translucent. Female imago (Fig. 4). Length (mm): body, 3.0– 3.5; forewings, 2.8–3.2; fore leg (from base of trochanter to apex of claw), 1.5; caudal filaments, 2.1–2.5. Color pattern as in male. Abdominal sternum 9 rounded, not projected. Eggs light yellow. Nymph. Unknown. Etymology. The specific epithet teipunensis is a combination of "tei-pun" (meaning “sabana”, according to the Pemon indigenous group from "La Gran Sabana", our study area) and the Latin suffix "-ensis" (denoting place or locality). Diagnosis. Male imagos of Caenis teipunensis sp. nov. can be distinguished from all other species in the genus by the following combination of characters: 1) length of body, 3.0– 3.6 mm, and of forewings, 2.5–2.9 mm; 2) presternal triangle anteriorly pointed (Fig. 2); 3) fore legs 0.6–0.7 times the length of body; 4) finger-like process on abdominal tergum 2 and lateral processes on other abdominal segments absent; 5) cerci 2.1–2.5 times the length of body; 6) styliger plate with elongated and oval central sclerite, apophyses strongly developed, wide and long (Figs. 3, 5); 7) penes (Figs. 3, 5) completely fused, laterally constricted, lateral lobes rounded, small tubercles and shallow grooves present on ventral surface; 8) forceps sclerotized, sharp, generally with small tubercles and setae on outer basal margin (Figs. 6 a–f), forceps 7.3–9.5 times longer than width at the middle. Discussion. Except for the extremely long apophyses of the styliger sclerite and shape of the forceps, Caenis teipunensis sp. nov. is similar to C. fittkaui Malzacher, and belongs to the same group of species defined by the apically pointed forceps (Malzacher 2001). Ecology. Imagos were collected along the stream margins, at night, and during the rainy season (November 2005 and June 2007), by using light traps. Streams flow through an upland undulating savanna ecosystem (913– 1355 m) and they were partially shaded (Kaku-Parú, Fig. 23) or not shaded at all (Kavanayén, Fig. 24). They were small to medium size streams (18–20 m wide), of low order (1 st– 2 nd), with shallow (8–32 cm) and acidic (pH = 5) waters, and with bottoms mainly composed of bed-rock (Kavanayén) and gravels (Kaku-Parú).

Caenis pycnacantha sp. nov. Mature larvae (in alcohol): Body length 3.6���5.4 mm, caudal filaments 3.7���4.9 mm. Body generally pale to slightly pale brown or brown. Vertex dark brown with pale ecdysis suture. Ocelli pale, compound eyes dark black (Figs. 1, 12���13). Mouthparts: labrum slightly concave medially, and with dense short hair and spines on anterior margin and dorsal surface (Fig. 2). Mandibles: with long marginal setae on surface and seven to eight spines on inner margin. Left mandible (Fig. 3): outer incisor with three denticles while inner incisor with two; prostheca clavate, with long fine setae and two sharp bristles at apex. Right mandible (Fig. 4): both of the incisors with two denticles, the apex of prostheca represented by a tuft of branched setae. Maxillae (Fig. 5) with 3 obvious bristles at apex and scattered long, fine setae and spines along inner and outer margin. Maxillary palpi segment 2 is the shortest in the three segments (length ratio of them: 1: 0.7: 1.1); segment 1 and 3 with sparse long hair and short spines along both inner and outer margins while segment 2 with three long setae on outer margin subapically only. Segment 1 and 2 of labial palpi subequal in length, segment 3 shorter than any of them; segment 2 and 3 decorated with dense long setae. Glossae and paraglossae with dense tiny setae at apex (Fig. 6). Hypopharynx shown in figure 7, superlinguae with a row of long hair along free margin (Fig. 7). Thorax: Pronotum expanded outwards slightly, with three irregular pale spots dorsally, a narrow and shallow subanterior ridge located near anterior margin; anterolateral angles of pronotum expanded forwards slightly, lateral margin with sparse hairs. Mesonotum with small expanded anterolateral lobes, a pair of coneshaped pale dots near anterior margin; medial line prominent, forming a longitudinal ridge sometimes. Legs pale brown, with dense setae and spines; femora with blackish brown band apically; forefemur with a row of transverse spine-like setae near apex (Figs. 1, 12); Length ratio of femora: tibiae: tarsi of foreleg = 1.5: 1.0: 1.0; claw single, with 6 denticles at base. Tibiae and tarsi pale brown. Mid- and hindlegs with similar color pattern but without transverse setae on femora; mid claw with 8���10 denticles at base, hind claw with many denticles from base to subapex, basal 3 ones slightly larger. Abdomen: terga 1, 2, 10 darker than others; terga 7���9 with three longitudinal pale stripes, one median, two near middle line (Figs. 1, 12); terga 2���9 with sharp posterolateral projections; a row of strong and acute denticle on posterior margin of each sternum. Apex of sternum 9 with blunt margin. Operculate gill 2 subquadrate; dorsal surface pale-brown, color pattern similar to abdominal terga; Y-shape ranges distinct, with dense setae along free margins and few longer setae on lateral edge; ventral surface of gills 2 with tiny palmate outgrowths near outer and posterior margins (Figs. 14���15). Caudal filaments pale, with sparse setae between segments. Male imago (in alcohol): Body length 2.8 mm, caudal filaments 8.0 mm. Head and thorax dark brown; abdomen pale, with diffused brown marks (Fig. 16). Antennae pale, pedicel 1.5X as long as scape, flagellum expanded at base and tapered to apex (Fig. 8). Ocelli pale, compound eyes dark brown. Forefemur washed with brownish black markings; mid and hind femora pale; forefemur: tibiae: tarsi=1.0: 2.9: 1.9; femora of all legs with slightly pigmented apex; legs with paired claws, one hooked, one blunt. Wing pale, transparent, with brown veins, subcosta robust, yellow-brown (Figs. 9, 16). Genitalia: forceps covered with dense, tiny setae on surface; four spines located on the apex. Penis lobes fused, posterior margin with slight median emargination. Styliger plate pale yellow, with brown markings on the middle of the base (Figs. 10���11, 17��� 18). Caudal filaments pale. Female imago (in alcohol): Body length 2.6 mm, caudal filaments 1.3 mm. Similar to male. Etymology. The epithet pycnacantha is from the Latin pycnacanthus (dense), in reference to the surface of the forceps which are covered with dense, tiny setae. Diagnosis and discussion. To date only six Caenis species have been reported from Chinese Mainland (Eaton 1884; Klap��lek 1905; Ulmer 1936; Zhou et al. 1997, 2000; Gui et al. 1999; Zhou & Zheng 2004). C. pycnacantha sp. nov. is similar to C. nigropunctata (see Ulmer 1940) because both have three longitudinal pale stripes on larval abdominal terga 7���9, and the forceps have dense setae on the surface and spines on the apex. However, they can be separated by the following characters: 1. The larval legs of C. pycnacantha sp. nov. have obvious dark brown markings, which are absent in C. nigropunctata; 2. The larval abdomen of C. nigropunctata is slightly paler than in C. pycnacantha sp. nov., especially that of terga 10; 3. The apical segment of maxillary palpi of C. pycnacantha sp. nov. is slightly longer than second one, but those of C. nigropunctata are subequal; 4.The adult antennae of the new species are pale and the flagellum is slightly expanded at the base; in C. nigropunctata the antennal base is broader. Moreover, in the male imago of C. pycnacantha sp. nov., the forceps have four large spines at apex compared against C. nigropunctata with a tuft of spines on the same position. Kang & Yang (1994, 1996) and Tong & Dudgeon (2002) described totally 10 Caenis species from Chinese Taiwan and Hong Kong area, but all of them are reported from larval stages only and are distinguished by color pattern and/or mandibular seta number or length. It is believed here that those characters can vary in certain level. Without imaginal materials, it is very difficult to compare the new species here to these species. Malzacher (1984) divided the European Caenis species into two lineages based on forceps characteristics: horaria ���lineage (with straight, strongly sclerotised tips of forceps) and macrura -lineage (bent forceps with some bristles or a tuft of long spines on tips). The macrura -lineage is divided further into five species groups. C. pycnacantha sp. nov. can be placed into the macrura -lineage and macrura -group because of the apical spines on the forceps; it is distinguished from other members of the group by the dense setae on the surface of the forceps. Biology. Most nymphs of C. pycnacantha sp. nov. were collected from small pools in streams with sediments of thick leaves and soil. Nymphs were often found under surface of stones in water. This species can be found and collected in most seasons except cold winter (usually from end of November to February). The adults are easily reared from mature nymphal stage, those having dark wing pads can become adults in 2��� 3 days in the rearing tank. However, we did not find living adults during our daytime field collections or at light in the evening although some dead imagos were seen on the water surface during the day. Zhou et al. (2004) reported that in dawn the collect light can attract many caenid adults and subimagos. It is suspected the new species emerges in the early morning too. The width of streams during collection in Zijin Hill was about 1 m and depth of water was less than 40 cm (some places only 10 cm). The streams are often represented by small lentic pools and water flows under the stream bed in some sections. Except after rain, the streams flow slowly, less than 20 cm /s. There is a heavy tree canopy shading most of the stream (Fig. 19). Material examined. Holotype: 1 male, Ying-Tuo village, May 24, 2004, Peng-LI; Paratypes: 24 Nymphs, 6 males 20 females (reared from larvae in lab), same data as for holotype; 12 Nymphs, Ling-Gu-Si Temple, May 24, 2006, Peng-LI; 3 Nymphs, Water-side Pavilion, May 29, 2007, Dong LIU, Hui XIE and Shi-Lei WANG; 10 Nymphs, Ying-Tuo village, May 11, 2008, Shi-Lei WANG, Hui XIE, Yan-Yan JIA and Ping CHEN; 2 Nymphs, Ying-Tuo village, Sep. 22, 2008, Shi-Lei WANG, Yan-Yan JIA and Ping CHEN. All types and specimens are collected from Zijin Hill, Nanjing City, Jiangsu Province, China and deposited in the Mayfly Collection, College of Life Sciences, Nanjing Normal University, China., Published as part of Jia, Yan-Yan, Qin, Jia-Zhang, Ju, Min & Zhou, Chang-Fa, 2010, A new mayfly species of Caenis from headwater of Zijin Hill (Nanjing, Eastern China) (Ephemeroptera: Caenidae), pp. 61-68 in Zootaxa 2535 on pages 61-67, DOI: 10.5281/zenodo.196612, {"references":["Eaton, A. E. (1884) A revisional monograph of recent Ephemeridae or mayflies. Transactions of the Linnaeus Society of Londo n, Second series, Zoology, vol. 3, part 2, 77 - 152.","Klapalek, F. (1905) Plecopteren und Ephemeriden aus Java, gesammelt von Prof. K. Kraepelin 1904. Mitteilungen aus dem Naturhistorischen Museum in Hamburg, 22, 103 - 107.","Ulmer, G. (1936) Neue Chinesische Ephemeropteren, Nebst Ubersicht Uber die bisher aus China bekannten Arten. Peking Natural History Bulletin, 10 (3), 210 - 215.","Zhou, C. F., Gui, H. & Su, C. R. (1997) Three new species of Ephemeroptera (Insecta) from Henan Province of China. Entomotaxonomia, 19, 268 - 272 (in Chinese).","Zhou, C. F., Gui, H. & Sui, C. R. (2000) The first record of the genus Brachycercus in China with description of a new species (Ephemeroptera: Caenidae). Entomologia Sinica, 7, 132 - 134.","Zhou, C. F. & Zheng, L. Y. (2004) A Preliminary Study on the Genus Caenis (Ephemeroptera: Caenidae) form Chinese Mainland, with Description of a New Species. Entomotaxonomia, 26, 1 - 7.","Kang, S. C. & Yang, C. T. (1994) Caenidae of Taiwan (Ephemeroptera). Chinese Journal of Entomology, 14, 93 - 113.","Kang, S. C. & Yang, C. T. (1996) A new species of Caenis Stephens (Ephemeroptera: Caenidae) from Taiwan. Chinese Journal of Entomology, 16, 55 - 59.","Tong, X. L. & Dudgeon, D. (2002) Three new species of the genus Caenis from Hong Kong, China (Ephemeroptera: Caenidae). Journal of Zoological Research, 23 (3), 232 - 238.","Malzacher, P. (1984): Die europaischen Arten der Gattung Caenis Stephens (Insecta: Ephemeroptera). Stuttgarter Beitrage zur Naturkunde, Ser. A., 373 (48), 1 - 48."]}

Eight species of Caenis are reported from Argentina, and new records are given for Bolivia, Brazil and Uruguay. The nymphs of five of them are firstly described from reared material: Caenis burmeisteri, C. dominguezi, C. gonseri, C. tenella new combination, and C. ludicra. Female adult stage of all these species (except C. tenella) are also firstly described. The new combination Caenis tenella is proposed, and the name Caenis grimi is here treated as a junior synonym of it. Caenis uruzu new species is described from male imagos and nymphs. New distributional records from Argentina and Uruguay are given. Diagnosis and illustrations to distinguish all the treated species from other Caenis species are proposed. A key to adults and nymphs from Argentinean species of Caenis is provided. Se reportan ocho especies de Caenis en Argentina y se dan nuevos registros para Bolivia, Brasil y Uruguay. Se describen por primera vez las ninfas de cinco especies, a partir de material criado: Caenis burmeisteri, C. dominguezi, C. gonseri, C. tenella nueva combinación, y C. ludicra. Las hembras adultas de estas cinco especies (excepto C. tenella) son descriptas también por primera vez. Se propone la nueva combinación Caenis tenella, y Caenis grimi es tratada como sinónimo junior de ésta. Caenis uruzu nueva especie es descripta de imagos macho y ninfas. Se brindan nuevos registros distribucionales para Argentina y Uruguay. Se proponen diagnosis e ilustraciones para distinguir todas las especies tratadas del género. Se provee una clave para la identificación de las ninfas y adultos de las especies argentinas de Caenis. Fil: Molineri, Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Biodiversidad Neotropical. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto de Biodiversidad Neotropical. Instituto de Biodiversidad Neotropical; Argentina Fil: Malzacher, Peter. Friedrich-Ebert-Str; Alemania

Caenis gonseri Malzacher (Figs. 50���65, 145��� 146) Caenis gonseri Malzacher, 2001: 11 (male). Type material. Paratypes 10 male imagos from CHILE, r��o Choapa, 13 -VI- 1986, T. Gonser col. (IFML). Additional material (IFML). Four male and 1 female imagos, 2 female subimagos, and 2 nymphal exuviae from ARGENTINA: Neuqu��n, Bajada del Agrio, RN 40, 70 km N de Zapala, R��o Agrio, 12 -XII- 1997, C. Molineri col. Male imago. Length: body, 3.6���3.8 mm; foreleg, 3.2���3.5 mm; fore wing, 3.7 ���4.0 mm. As Malzacher (2001: 11) had thoroughly described the male imago, a redescription will not be included here. Only one difference was found when checking the four males from Neuqu��n with Malzacher��s description: the finger-like process on abdominal tergum II is not visible, probably because it is pressed against the abdomen. This feature is assumed to be present in males, since it is well visible in the females collected with them. Female (imago and subimago). Length: body, 5.7 ���6.0 mm; fore wing, 4.2���4.6 mm. Antennae yellowish; occiput with a transverse blackish line connecting lateral ocelli. Thorax. Pronotum with relatively acute anterolateral projections, gray shading forming a quadrangular empty mark medially; prosternal triangle (Fig. 50) anteriorly blunt, as in males. Katepisternum as dark as the remaining thoracic sclerites. Abdomen shaded with gray on broad transverse bands, mediolongitudinal line paler, bordered by a pair of submedian darker lines; abdomen ventrally paler, very lightly shaded gray, somewhat stronger laterally. Posterolateral filaments of abdomen present on segments IV���IX (Figs. 53���54), longer than in male, those of segments IV���VII are longer than the rest. Finger-like process of abdominal tergum II present, short (Fig. 55). Ninth sternum broadly rounded posteriorly (Fig. 52). Egg mass yellowish. Nymphal exuviae. Length of male: body, 5.0 mm; caudal filaments, 3.5 mm. Length of female: body, 6.0 mm; caudal filaments, 4.0 mm. Head: with a pair of pale blotches on sublateral zones of occiput; hind margin of head with small simple setules. Mouthparts: labrum with broad and smooth anteromedian emargination, mandibles as in Figs. 145���146; segment II of labial palp 1.44 times the length of segment III. Thorax. Pronotum anteriorly projected as in Fig. 56. Pale blotches present on mesonotum: 1 small circular blotch in the median zone of anteronotal projection, and 4 paired blotches on anterior half of mesonotum (the larger pair near the base of wingpads, the other three much smaller and located between the others). Legs as in Figs. 63��� 65. Coxal processes very short and rounded. All tarsi with one row of simple setae, hind tarsi with an additional row of serrated setae. Tarsal claws (Figs. 57���59) relatively straight, fore and middle claws with 4���5 weakly marked denticles, hind claws with about 20 denticles. Abdomen. Dorsal projection of tergum II short (Fig. 55). Operculate gills with simple setae dorsally, microtrichia on ventral submarginal row elongated to subtriangular. Ninth sternum apically rounded, hind margin with simple setae, few setae apically bent inwards. Diagnosis. Caenis gonseri can be distinguished from the other species of the genus by the following combination of characters. In the imago: 1) general coloration yellowish-brown; 2) prosternal triangle anteriorly blunt (Fig. 50); 3) median filament on abdominal tergum II short (Fig. 51); 4) fore legs 0.9 times length of body; 5) forceps apically rounded, with small projections apically; 6) central sclerite of styliger circular; 7) apophyses of styliger sclerite, long and broad; 8) lobes of penes generally with straight hind margin, lateral lobes rounded and slightly projected; 9) color of katepisternum similar to the rest of thoracic sclerites; 10) posterolateral filaments present on abdominal segments IV���IX, longer on IV���VII (Figs. 53���54). In the nymph: 1) as only the nymphal exuvia is known, the epidermic coloration of the head was not available, a pair of pale blotches is present on sublateral zones of occiput, hind margin of head with small simple setules; 2) meso- and metacoxal processes present but narrow; 3) serrated setae only in hind tarsi (Fig. 62); 4) tarsal claws relatively slender (denticles apparently worn out) (Figs. 57���59); 5) abdominal color pattern unknown, posteromedian projection of abdominal tergum II relatively short (Fig. 55); 6) labrum with shallow and smooth anteromedian emargination; 7) segment II of labial palp 1.44 times the length of segment III; 8) lingua of hypopharynx with concave fore margin (similar to Fig. 156); 9) IX sternum apically rounded, hind margin with simple setae, few setae apically bent inwards; 10) dorsum of gill II only with simple setae; 11) dorsum of all femora with numerous long spines (Figs. 63���65). Distribution (Fig. 188). Argentina (Neuqu��n, R��o Negro), Chile., Published as part of Molineri, Carlos & Malzacher, Peter, 2007, South American Caenis Stephens (Ephemeroptera, Caenidae), new species and stage descriptions, pp. 1-31 in Zootaxa 1660 on pages 14-16, DOI: 10.5281/zenodo.179923, {"references":["Malzacher, P. (2001) South and Central American Caenis species with rounded forceps tips (Insecta: Ephemeroptera: Caenidae). Stuttgarter Beitrage zur Naturkunde Ser. A, 626, 1 - 20."]}

Caenis argentina Navas (Figs. 1���14, 139��� 140, 158, 165, 172, 179) Caenis argentina Navas, 1915: 12 (male); Hubbard, 1982: 261; Malzacher, 2001: 2 (male, female, nymph, egg). Type material (IFML): Lectotype male imago and seven male imagos paralectotypes from ARGENTINA: Buenos Aires, Tandil, arroyo Quequ��n Chico, 7 -I- 1983, E. Dom��nguez col. Additional material (IFML): Two nymphs, 1 female subimago and 1 nymphal exuviae, same data as lectotype; 9 nymphs from ARGENTINA: Buenos Aires, Tandil, arroyo Chapaleof��, 9 -I- 1983, E. Dom��nguez; 6 nymphs from Buenos Aires, Pueyrred��n, Laguna de los Padres, 10 -II- 2002, M. A. Gonz��lez-Sagrario col.; 3 nymphs and 1 female subimago from Santiago del Estero, Termas de R��o Hondo, La Olla, R��o Dulce, 15 -VIII- 2004, C. Molineri col.; 2 male and 3 female adults, reared from nymphs, from Tucum��n, Dpto. Burruyacu, Timb�� Viejo, R��o Sal��, 27 -IV- 2004, C. Molineri & C. Nieto cols.; 12 nymphs from Tucum��n, Ranchillos, canal DP2, 6-V- 2006, C. Molineri col.; 1 nymph from Tucum��n, Acheral, Laguna sobre arroyo Hollinado, cruce RP 38, 28-VII- 2006, C. Molineri col.; 1 nymph from Catamarca, Ba��ado de Ovanta, S 28 �� 08' ��� W 65 �� 19 ', 24 -VIII- 2004, M. Peralta col. Male imagos of C. argentina were thoroughly described by Malzacher (2001). Female imagos, as reported by Malzacher (2001) are similar to males, except that prosternal triangle is anteriorly truncated. Malzacher (2001) also described the nymphs of C. argentina. A list of characters useful to distinguish female imagos and nymphs follows. Female imago. Occiput with a pair of paramedian grayish marks forming two concentric semicircles; pronotum with a pair of submedian black spots; all femora with preapical blackish bands; coloration of mesothoracic katepisternum (largest sclerite on the anteroventral corners of mesothorax) similar to rest of mesothorax; thoracic and abdominal sterna with well marked median grayish spots; abdominal sterna also with paramedian spots and with wide whitish zones medially and laterally; posterolateral filaments of abdominal segments long. Mature nymph (Fig. 158). General coloration yellowish-brown, pale blotches present on head (along median line and in sublateral zone of occiput), pronotum (posteromedian triangular zone), and mesonotum (irregular blotches near anterior margin, and three well marked pairs of lateral to sublateral circular blotches between wing bud bases). Head with paramedian gray marks on occiput (Fig. 165), similar to those of female; hind margin of the head with long laterally directed setae and frayed microtrichia. Mandibles as in Figs. 139��� 140; segment II of labial palp 1.36���1.63 times the length of segment III. Thorax. Pronotum with a pair of paramedian black dots. Meso and metasternum with a gray elongated median mark. Legs (Figs. 12���14) whitish to yellowish, coxae II and III with broadly rounded projections (Figs. 1���2); all femora with preapical blackish bands (Figs. 12���14), dorsum of femora with few and weak setae, transversal row of setae on dorsum of fore femora reduced, only with 2���5 setae (Figs. 10, 12); tibiae and tarsi of all legs with basal dark-yellow bands; tarsi with longitudinal row of long and slender spine-like setae at medial margin (Fig. 11), tarsi II and III (Figs. 13���14) with an additional submarginal row of serrated setae (Fig. 9); tarsal claws strongly curved apically (Figs. 3���5), tarsal claws I���II with 4���8 denticles, tarsal claw III with 10���20 denticles. Abdomen. Terga with broad pale zones laterally and medially (Fig. 172), abdominal sterna with distinct median and paramedian gray spots (Fig. 179). Operculate gills dorsally with small maculae slightly darker than the rest (Figs. 158, 172); dorsal microtrichia bifid and relatively slender (Fig. 6), microtrichia on ventral submarginal row elongated (Figs. 7���8). Posterolateral spines on abdominal segments very well developed. Caudal filaments whitish with dark joinings. Sternum IX apically rounded, setae on hind margin strong and apically bent inwards. Diagnosis. Caenis argentina can be distinguished from all other species of Caenis by the following combination of characters. In the imago: 1) general coloration yellowish-brown; 2) prosternal triangle anteriorly pointed in males, with concave sides, truncated in females; 3) median filament on abdominal tergum II long; 4) fore legs 0.8���1 times length of body; 5) forceps apically rounded; 6) central sclerite of styliger elongated; 7) apophyses of styliger long and straight; 8) penes with rounded lobes and straight or slightly convex posterior margin; 9) coloration of mesothoracic katepisternum similar to rest of mesothorax. In the nymph: 1) head color pattern as in Fig. 165, hind margin with long laterally directed setae and frayed microtrichia; 2) meso- and metacoxal processes present but relatively small (Figs. 1���2); 3) tarsi with relatively slender setae, many of them serrated; 4) tarsal claws curved apically, tarsal claws I���II with 4���8 denticles, tarsal claw III with 10���20 denticles (Figs. 3���5); 5) abdominal color pattern as in Fig. 172; 6) labrum with slightly rounded lateral margins (similar to Fig. 31); 7) segment II of labial palp 1.36���1.63 times the length of segment III; 8) lingua of hypopharynx with concave fore margin (similar to Fig. 156); 9) sternum IX apically rounded, setae on hind margin strong and apically bent inwards (similar to Fig. 7 b in Malzacher 2001). Distribution (Fig. 185). Argentina (Buenos Aires, Santiago del Estero, Catamarca, Tucum��n)., Published as part of Molineri, Carlos & Malzacher, Peter, 2007, South American Caenis Stephens (Ephemeroptera, Caenidae), new species and stage descriptions, pp. 1-31 in Zootaxa 1660 on pages 7-9, DOI: 10.5281/zenodo.179923, {"references":["Navas, L. (1915) Neuropteros sudamericanos. Segunda Serie. Broteria (Serie Zoologica), 13, 5 - 13.","Hubbard, M. D. (1982) Catalogo abbreviado de Ephemeroptera da America do Sul. Papeis Avulsos de Zoologia, 34, 257 - 282.","Malzacher, P. (2001) South and Central American Caenis species with rounded forceps tips (Insecta: Ephemeroptera: Caenidae). Stuttgarter Beitrage zur Naturkunde Ser. A, 626, 1 - 20."]}

Caenis ludicra Navas (Figs. 66���85, 149��� 150, 161, 169, 177) Caenis ludiera [sic] Navas, 1920: 54 (male); Alba-Tercedor & Peters, 1985: 219. Caenis ludicra; Navas, 1922: 199; Navas, 1924: 359; Navas, 1930 a: 130; Navas, 1930 b: 360; Navas, 1931: 322; Hub- bard, 1982: 261; Dom��nguez, 1989: 272; Malzacher, 2001: 6 (male, nymph). Ordella ludicra; Lestage, 1931: 59. Type material. Not revised, but the material listed below was determined by comparison with the lectotype (Malzacher, 2001). Four male imagos from ARGENTINA: C��rdoba, San Esteban, 10 -X- 1981, E. Dom��nguez col.; 14 male and 1 female (female not listed in Malzacher, 2001) imagos from Tucum��n, Lules, arroyo Las Vertientes, 28 -VIII- 1981, E. Dom��nguez col. (IFML). Additional material (IFML). ARGENTINA: C��rdoba, R��o Cuarto, Paso del Cuco, Rodeo Viejo, 8 -X- 1993, M. Gualdoni col.; C��rdoba, San Esteban, r��o San Esteban, S 27 �� 15 ' ��� W 65 �� 32 ', 1 -X- 1999, V. Manzo & S. Cohen cols.; C��rdoba, Cavalanga, Arroyo Las Salinas, S 31 �� 23 ' ��� W 64 �� 32 ', 2 -X- 1999, V. Manzo & S. Cohen cols.; Catamarca, Guayamba, r��o El Durazno, S 28 �� 21 ' 06" ��� W 65 �� 25 ' 53 ", 670 m, 8 -II- 2000, C. Molineri col.; Catamarca, dpto. Andalgal��, Las Estancias, El Lindero, S 27 �� 28 ' 01" ��� W 66 �� 00' 37 ", 1530 m, 19 -IV- 2003, E. Dom��nguez & G. Cuezzo cols.; Catamarca, Ba��ado de Ovanta, S 28 �� 08' ��� W 65 �� 19 ', 24 -VIII- 2004, M. Peralta col.; Tucum��n, Las Salas, r��o San Javier, 7 -X- 1998, E. Dom��nguez; Tucum��n, Escaba, r��o Singuil, 12 -XI- 1999, C. Molineri col.; Tucum��n, El Siamb��n, arroyo de la Gomer��a, 22 -VIII- 2004, C. Molineri col.; Tucum��n, Raco, arroyo Palangana, VII- 2004, CM; Tucum��n, Dique El Cadillal, Ticucho, 12 -X- 1998, C. Molineri col.; Tucum��n, Taf�� del Valle, La Angostura, r��o Los Sosa, 2000 m, 5 -XI- 1995, C. Molineri col.; Salta, Finca Jak��lica, S 22 �� 41 ' 01" ��� W 64 �� 30 ' 40 ", 630 m, 14 -XII- 1999, E. Dom��nguez; Salta, Los Toldos, 27 -X- 1983, E. Dom��nguez; Salta, P. N. Barit��, r��o Barit��, 16 -IX- 1981, E. Dom��nguez; Salta, Vaqueros, r��o Calderas, S 24 �� 39 ' 45 " ��� W 65 �� 23 ' 02", 1260 m, 2 -III- 2000, C. Molineri col.; Salta, Guachipas, r��o Grande del Sauce, 15 -IX- 1998, C. Molineri col.; Jujuy, San Salvador de Jujuy, r��o Lozano, 26 -VI- 1997, CM; Jujuy, Tiraxi, r��o de las Capillas, 27 -XII- 1998, W. Ciares & C. Rueda cols.; Jujuy, Palpal��, r��o Zapla, 26 -VI- 1997, C. Molineri col.; Jujuy, El Carmen, arroyo Las Lanzas, S 24 �� 27 ' 17 " ��� W 65 �� 17 ' 48 ", 1250 m, 3 -III- 2000, E. Dom��nguez & C. Molineri col. BOLIVIA: Tarija, O'Connor, ca. Entre R��os, r��o Salinas, 1160 m, S 21 �� 38 ' 45 " ��� W 64 �� 09' 08", 6 -X- 2004, C. Molineri col.; same except r��o Saic��n, 1000 m, S 21 �� 46 ' 28 " ��� W 64 �� 05' 24 ", 7 -X- 2004, C. Molineri col.; Tarija, Arce, ca. La Mamora, r��o Orosa, 1100 m, S 22 �� 12 ' 09" ��� W 64 �� 37 ' 37 ", 5 - X- 2004, C. Molineri col.; Tarija, Quebrada el Molino, r��o Molino, S 21 �� 35 ' 35.7 " ��� W 64 �� 46 ' 4.7 ", 1907 m, 25 -II- 2006, C. Nieto & P. Rueda cols.; Tarija, r��o Villa, S 21 �� 22 ' 57.8 " ��� W 64 �� 16 ' 55.1 ", 1816 m, 5 -III- 2006, E. Dom��nguez & C. Nieto cols.; Tarija, Sidras, r��o Ita��, S 22 �� 05' 37.1 " ��� W 63 �� 59 ' 12.7 ", 593 m, 8 -III- 2006, E. Dom��nguez & C. Nieto cols. Male imago. As Malzacher (2001) reported, male imagos of C. ludicra show an almost circular central sclerite of the styliger plate, and the general coloration is generally very dark. Nevertheless, some populations in NW Argentina may show a lighter general coloration. Here the description of the female imago and nymphs of C. ludicra based upon reared material from both sexes is presented. Description and figures of male imago should be consulted from Malzacher (2001). Female imago. Length: fore wings, 4.0��� 5.3 mm; body, 4.7���5.7 mm; caudal filaments, 3.3���3.5 mm. General coloration orangish-brown to dark grayish-brown. Head: occiput with grayish reticulated marks. Femora without marks but sometimes femora II and III with small grayish subapical spots. Pronotum with a pair of submedian whitish circular marks. Mesothoracic katepisternum much lighter than the rest of mesothorax. Abdominal terga uniformly shaded brownish-gray on paramedian marks; gill sockets paler; terga VII���IX with oval pale marks on lateral margins, similar contiguous marks present on sterna. Thoracic and abdominal sterna without well marked spots, specially on lateral margins; lateral filaments of abdomen medium length. IX sternum apically rounded. Caudal filaments whitish except basal and subbasal segments yellowish-brown. Mature nymph (Fig. 161). Length of male: body, 4.0���5.0 mm; caudal filaments, 3.2���3.5 mm. Length of female: body, 6.0��� 6.3 mm; caudal filaments, 3.5���4.7 mm. Head paler on occiput, with submedian grayish marks (Fig. 169); hind margin of head with small frayed microtrichia. Mouthparts: segment II of labial palp 1.63���1.82 times the length of segment III. Thorax. Thorax yellowish to brownish, gray to black shading (variable). Pronotum with a pair of submedian large pale areas (Fig. 161). Mesonotum with one pair of submedian pale blotches, and another pair on wingpad bases (Fig. 161). Metanotum and thoracic sterna paler than dorsum. Legs: meso- and metacoxal processes well developed (Figs. 66���67); femora only with slightly gray spots on subapex (Figs. 83���85), femora with numerous weak setae at dorsum, dorsum of femora I with a transverse row of 6���8 setae at apical 1 / 3 (Figs. 79, 83); tibiae and tarsi with basal band very slightly darker than the rest; all tarsi with a marginal row of spine-like setae, tarsi III with an additional submarginal row of serrated setae (Fig. 81); tarsal claws relatively straight (Figs. 71���73) to very slightly curved apically (Figs. 68���70), tarsal claws I���II with 4���6 denticles (Figs. 69 ���70, 72��� 73), tarsal claw III with 27���33 denticles (Figs. 68, 71). Abdomen. Paler areas on abdominal terga generally forming a pair of submedian pale bands on segments VII���IX (Fig. 175). Abdominal sterna shaded with gray but generally without distinct dark spots (similar to Fig. 184). Operculate gills generally without darker spots, uniformly brown; dorsal microtrichia bifid, widely subdivided (Fig. 74), stout microtrichia on ventral submarginal row (Fig. 75���76). Gills III���VI bicolor, half white and half gray. Sternum IX rounded apically, setae on hind margin strong and apically bent inwards. Caudal filaments whitish, darker only at basal segment. Diagnosis. Caenis ludicra can be distinguished from the other species of Caenis by the following combination of characters. In the imago: 1) general coloration blackish-brown; 2) prosternal triangle anteriorly truncated in both sexes; 3) median filament on abdominal tergum II long; 4) fore legs 0.9���1.1 times length of body; 5) forceps apically rounded; 6) central sclerite of styliger circular; 7) apophyses of styliger sclerite short and rounded; 8) penis lobes rounded, more or less tapering, hind margin convex; 9) coloration of mesothoracic katepisternum paler than rest of mesothorax. In the nymph: 1) head color pattern as in Fig. 169, hind margin with small frayed microtrichia; 2) meso- and metacoxal processes present and pointed (Figs. 66���67); 3) tarsi with relatively stout setae, only few of them serrated; 4) tarsal claws generally not strongly curved apically (Figs. 68���73); 5) abdominal color pattern as in Fig. 175; 6) labrum with slightly rounded lateral margins; 7) segment II of labial palp 1.63���1.82 times the length of segment III; 8) lingua of hypopharynx with concave fore margin (similar to Fig. 156); 9) IX sternum rounded apically, setae on hind margin strong and apically bent inwards; 10) microtrichia from dorsum of body and operculate gills ramified (Fig. 74); 11) gills III���VI bicolor, half white and half gray. Two species are sympatric with C. ludicra, C. argentina and C. dominguezi. In C. ludicra pale blotches are less extended than in C. argentina (the most distinct are a submedian pair on mesonotum); and the occiput show dark pigments (Fig. 169), not present in C. dominguezi (Fig. 167). Discussion. Malzacher (2001) described nymphs of " C. ludicra group" from Brazil, as probably pertaining to C. ludicra, but this species appears to be restricted to Southern Bolivia and Northwestern Argentina. The nymphs described by Malzacher are very similar to C. ludicra nymphs but represents another species (see C. uruzu new species, below). Distribution (Fig. 187). Argentina (C��rdoba, Catamarca, Tucum��n, Salta, Jujuy), Bolivia (Tarija). This species, quite common in NW Argentina, was also collected in Southern Bolivia. The distributional records include localities from mountain rain forest (Yungas), and drier habitats as Chaco, Monte and transitional regions. Caenis plaumanni Malzacher (86���95, 151 ��� 152, 163, 170, 177, 183) Caenis plaumanni Malzacher, 2001: 13 (male, nymph). Material (IFML). One male imago and 5 nymphs from ARGENTINA: Misiones, 10 km NE de San Vicente, INTA Cuartel Victoria, 30 -XI- 1986, E. Dom��nguez col.; 1 male imago Misiones, P.P. Urugua-��, arroyo Uruz��, S 25 �� 51 ' ��� W 54 �� 10 ', 322 m, 23-24 -XI- 1998, E. Dom��nguez et al. cols.; 4 nymphs Misiones, 25 km S El Soberbio, 21 -XI- 1998, E. Dom��nguez et al. cols.; 1 nymph Misiones, Candelaria, 2 km E Bonpland, r��o del Camping, 15 -II- 1985, E. Dom��nguez col.; 1 nymph idem before except date 18 -XI- 1998; 7 nymphs Misiones, 15 km E San Jos��, RP 203, arroyo San Juan, 17 -XI- 1998, E. Dom��nguez et al. cols.; 2 nymphs Misiones, San Pedro, confluencia r��os Alegr��a y Pirai-Guazu, 22-23 -XI- 1998, E. Dom��nguez et al. cols.; and 2 nymphs Misiones, INTA Cerro Azul, arroyo Tacuar��, 17 -XI- 1998, E. Dom��nguez et al. cols. Descriptions of male imagos and nymphs of C. plaumanni can be found in Malzacher (2001). Diagnosis. Malzacher (2001) had thoroughly described the male imago. Caenis plaumanni, known from male imagos and nymphs, can be distinguished from the other species of Caenis by the following combination of characters. In the imago: 1) general coloration yellowish brown; 2) prosternal triangle anteriorly pointed or rounded; 3) median filament on abdominal tergum II long; 4) fore legs 1.1 times length of body; 5) forceps apically rounded (Figs. 7 c���e in Malzacher 2001); 6) central sclerite of styliger subcircular (Fig. 7 a in Malzacher 2001); 7) apophyses of styliger sclerite long, thin, and relatively far from forceps bases; 8) penes lobes rounded, hind margin convex. In the nymph (Fig. 163): 1) head color pattern as in Fig. 170, hind margin with scale-shaped microtrichia, surface of the head completely covered by short triangular spinules; 2) meso- and metacoxal processes semicircular (Fig. 92); 3) middle and hind tarsi with one row of simple setae, and another of serrated setae; 4) tarsal claws generally curved apically (Figs. 86���88); 5) abdominal color pattern as in Figs. 177 and 183; 6) labrum with slightly rounded lateral margins; 7) segment II of labial palp 1.55���1.68 times the length of segment III; 8) lingua of hypopharynx with concave fore margin (similar to Fig. 156); 9) IX sternum apically rounded, setae on hind margin strong and apically bent inwards; 10) scale-shaped microtrichia present on dorsum of body and gills II (Figs. 8 i���j in Malzacher 2001). Distribution (Fig. 187). Argentina (Misiones), Brazil (Rio Grande do Sul)., Published as part of Molineri, Carlos & Malzacher, Peter, 2007, South American Caenis Stephens (Ephemeroptera, Caenidae), new species and stage descriptions, pp. 1-31 in Zootaxa 1660 on pages 16-21, DOI: 10.5281/zenodo.179923, {"references":["Navas, L. (1920) Insectos Sudamericanos. Tercera serie. Anales de la Sociedad Cientifica Argentina, 90, 52 - 72.","Alba-Tercedor, J. & W. L. Peters (1985) Types and additional specimens of Ephemeroptera studied by Longinos Navas in the Museo de Zoologia del Ayuntamiento, Barcelona, Spain. Aquatic Insects, 7, 215 - 227.","Navas, L. (1922) Estudis sobre Nevropters (Insectes). Arxivs d'Institvt de Ciencies (Barcelona), 7, 179 - 203.","Navas, L. (1924) Insectos de al Argentina y Chile. Estudios, 1922, 358 - 368.","Navas, L. (1930 a) Insectos de la Argentina. Sexta Serie. Revista de la Sociedad Entomologica Argentina, 3, 125 - 132.","Navas, L. (1930 b) Algunos insectos de Chile. Cuarta serie. Revista Chilena de Historia Natural, 34, 350 - 366.","Navas, L. (1931) Insectos de la Argentina. Septima serie. Revista de la Sociedad Entomologica Argentina, 3, 317 - 324.","Dominguez, E. (1989) Tipos de Ephemeroptera de L. Navas depositados en las colecciones entomologicas de la Argentina. Revista de la Sociedad Entomologica Argentina, 45, 271 - 274.","Malzacher, P. (2001) South and Central American Caenis species with rounded forceps tips (Insecta: Ephemeroptera: Caenidae). Stuttgarter Beitrage zur Naturkunde Ser. A, 626, 1 - 20.","Lestage, J. A. (1931) Contribution a l'etude des Ephemeropteres. VIII. Les Ephemeropteres du Chili. Bulletin et Annales de la Societe Entomologique de Belgique, 71, 41 - 60."]}