Search

X-ray diffraction (XRD), Scanning Electron Microscope-Energy Dispersive Spectroscopy (SEM-EDS), and Fourier Transform Infrared Spectroscopy (FT-IR), were applied to analyze the organic matrix of two Molluscan shells. The Mollusca shells are mineral structure and calcium carbonate crystallized as aragonite. The FT-IR spectra showed Alkyl Halide, Alkanes, Alcohols, Amides, Aromatic, and Hydroxyl groups in the organic matrix of the whole (organic and mineral) Molluscan shells. SEM images of particles of the two Molluscan shells at different magnifications were taken. The morphologies of the samples show a flake like structures with irregular grains, their sizes are at micrometric scale and the chemical analysis of EDS indicated that the major elements of Cardita and Gastropoda were C, O, and Ca, consistent with the results of XRD analysis. The results of the analysis of the EDS spectra of the shells showed that the content of most of the powder composition of shells is the element carbon, calcium oxygen, aluminium, and lead peaks that appear on the Cardita and Gastropoda and shells powders tap EDS spectra. The present work examined organic matrix of the selected shells of the heavily polluted and light polluted sites, along Nellore Coast, South East Coast of India. The heavily polluted sites have significantly thickened shells. The data demonstrated the sensitivity of this abundant and widely distributed intertidal fragile environment. Keywords: Mollusca shells, Organic matter, FTIR Spectroscopy, XRD, SEM and EDS analysis

In 2015 the locality Borač-Podolí was newly examined. The locality is situated 8 km NW from the town of Tišnov. A large amount of shallow-water fossils of middle Miocene (Badenian) age was collected. The state of preservation of the material enabled us bivalve borings of ichnogenus Gastrochaenolites which were bored into colonies of hermatype corals and other calcareous hard substrates. In some of these borings, bivalves were found in situ. The borings were determined as Gastrochaenolites isp., Gastrochaenolites orbicularis, Gastrochaenolites lapidicus, Gastrochaenolites dijugus and Gastrochaenolites torpedo. The in situ bivalves were determined as Gastrochaena cf. intermedia, Rocellaria cf. dubia, Hiatella arctica and Cardita calyculata. The first three species probably represent primary borers while Cardita calyculata is probably a secondary user (squatter). Based on an analysis of fossil material, we can assume that borings were created aft er the death of corals during the repeated transport of these bioclasts. It led to colonizing of the whole surface of coral bioclasts. The bioclasts were then moved to deeper water. Transport to water with clay sedimentation enabled the preservation of the bivalves in situ in borings.

Akardita n. gen. is described for a small Pliocene to Recent group of carditids. The type species is Cardita subrevoluta de Stefani, 1888, from the lower Pliocene of Italy. The new genus includes Akardita iberica n. sp., from the lower Pliocene of southern Spain, and Cardita (Venericardia) monodi Nicklès, 1953, an extant species from West Africa. A few additional Neogene species from Europe could turn out to be representatives of the new genus, whose disappearance from European seas seems to be related to an increasing cooling trend during the Neogene–Pleistocene interval. Because of the confused status of carditid taxonomy, about which some observations are reported in the present work, it is not possible to assign the new genus to any of the traditional subfamilies.

The population dynamics of the “cholga” Cardita affinis (Sowerby 1833) from Malaga Bay, Colombia, was studied from December 1999 to February 2002, which included the 1999–2000 La Nina event (LN) and the post-LN period 2001–2002. This climatic deviation caused precipitation anomalies in Malaga Bay. Salinity, precipitation, and sea surface temperature anomalies were highly correlated with the bivalve’s body mass cycle. Irregular spawning events were observed during LN by comparison with the regular period. Individual growth and mortality were found significantly higher during LN than during the post-LN period while longevity was almost twofold lower during LN. Increased mortality was probably related to environmental stress. Individual production and productivity were higher during LN, although the annual biomass was lower than during the post-LN period. These results may be related to higher food availability during LN, which agrees well with the results on growth performance. The observed changes provide a base line for future studies regarding effects of El Nino/LN events on population dynamics of tropical bivalves.

Based on the study of available types and extant collections, this paper provides a systematic revision of the living species of Carditoidea occurring in the Magellan and Perú-Chile Provinces. Out of the 19 nominal species reported for the area, eight species are recognized as valid: Cyclocardia compressa, C. spurca, C. thouarsii, C. velutina, Carditella naviformis,C. semen, C. tegulata and Carditopsis flabellum. Other eight nominal species are regarded as synonyms: Cardita magellanica of Cyclocardia velutina; Carditella pallida of C. tegulata; Cardita australis and Actinobolus philippi of Carditella naviformis; Cardium pygmaeum of Carditella semen; Cardita paeteliana of Cyclocardia spurca; Carditella pallida duodecimcostata of Carditopsis flabellum; and Cardita congelascens of Cyclocardia thouarsii. Furthermore, Cardita malvinae and Cardium parvulum are nomina dubia, and the occurrence of Carditella exulata in Magellanic waters is doubtful. Fil: Güller, Marina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; Argentina Fil: Zelaya, Diego Gabriel. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

An investigation of sperm ultrastructure in representatives of the marine bivalve families Carditidae (Carditoidea) and Crassatellidae (Crassatelloidea) reveals features o f taxonomic significance. Spermatozoa of Cardita muricata (Carditidae) and Eucrassatella cumingii, E. kingicola, Talabrica aurora (Crassatellidae) differ from the classic aquasperm type in having an elongate acrosomal vesicle and elongate nucleus. In addition, the midpiece region in these species is composed of a distinctive, and here considered t o be apomorphic. arrangement of 8 (rarely 7 or 9), tightly abutted mitochondria grouped around ii dense rod which is continuous with the distal centriole (basal body). A recognizable (i.e. triplet‐substructure) proximal centriole is therefore absent in mature spermatozoa of crassatellids and carditids. This situation contrasts with the presence of an unmodified proximal centriole in the spermatozoa o f all other investigated bivalves. Observations on crassatellid and carditid spermatids indicate that the dense r o d is derived through metamorphosis of the proximal centriole. The shared and highly characteristic midpiece features of spermatozoa of the Crassatellidae and Carditidae clearly indicate ii close relationship between these families and support the unification of the Crassatelloidea and Carditoidea into a single superfamily Carditoidea Fleming. 1820 (date priority over Crassatelloidea Ferussac. 1822). Copyright

Amino acid compositions of more than 550 individuals of three common subarctic/arctic molluscan genera, Hiatella, Mya, and Astarte, were measured to determine the feasibility of using such data to classify unidentifiable shell fragments belonging to one of these genera. To account for diagenetically induced variation in amino acid composition of the fossils, equations were developed to reconstruct the original composition of each shell based on its extent of amino acid epimerization. The classification procedure involved calculating the multivariate similarity (coefficient of similarity (CS)) between the adjusted amino acid composition of an unknown shell and that of a set of references. CSs were calculated for an additional 141 identifiable shells of the three common genera to evaluate the performance of the classification method; the procedure correctly classified 93% of the shells. In addition, CSs were calculated for 162 identifiable shells of five other common subarctic/arctic genera (Portlandia, Spisula, Macoma, Cardita, and Arctica) to test the ability of the method to discriminate shells belonging to genera not included in the reference set and are therefore necessarily misclassified. Overall, CSs for correctly classified shells ( x = 0.891 ) are higher than for misclassified shells ( x = 0.809 ), and the ratio of correctly to incorrectly classified individuals increases with increasing CS. Based on these empirical tests, only those classifications supported by CSs greater than 0.88 were considered reliable; and of these, approximately 6% may be misclassified. The classification procedure was applied to sixty-four unidentifiable molluscan shell fragments recovered from boreholes drilled onshore of Nome, Alaska, of which twenty-six were classified as Hiatella, Mya, or Astarte with a CS greater than 0.88.

Bivalve molluscs from the Western coast of Senegal were sampled and measured for their cadmium, copper and zinc concentrations. This part of Africa has not been studied as regards heavy metal concentrations in the molluscs. The collected species are two small African bivalve molluscs, living in the sand: Cardita ajar and Dosinia isocardia; the African mussel Perna perna which is the only mussel of this genus in the Western coast of Africa and the oyster Crassostrea gasar, which lives in mangroves attached to the rhizophores, in the intertidal zone. C. gasar and C. ajar present higher cadmium concentrations, respectively 6.82±0.54 and 13.77±0.80 μg Cd/g (d.w.) than the two other species (D. isocardia: 3.88±0.31 μg/g and P. perna 2.37±0.22 μg/g. Copper and zinc concentrations are in the range of the published values for C. gasar and P. perna collected elsewhere in Africa. The results suggest that cadmium may be present in high concentrations in Senegalese waters where upwellings occur. Keywords: Metals, Molluscs, Senegal, Mauritania, Crassostrea gasar, Perna perna, Cardita ajar, Dosinia isocardia, Donax rugosus

1. 1. The extracellular hemoglobin of the heterodont clam Cardita borealis has been purified and resembles other hemoglobins with respect to its absorption spectrum. 2. 2. The pigment chromatographs on Sepharose 4B with an apparent molecular weight of about 12 × 10 6 between pH 5.7 and 8 in the presence of Mg 2+ . The broad elution peak suggests heterogeneity with respect to molecular weight. Cardita hemoglobin can be dissociated at high pH (9.0–10.5) into a submultiple fraction which shows a broad peak on Sepharose 4B with an apparent molecular weight of about 1.4 × 10 6 . 3. 3. In the electron microscope, the 12 × 10 6 molecular weight hemoglobin molecules appear as rod shaped particles with approximate dimensions of 210 and 365 A in width and ranging in length from about 365 to 1200 A. This rod-like structure is not present in micrographs of the dissociated hemoglobin. 4. 4. The smallest subunit molecular weight of the hemoglobin as determined by SDS gel electrophoresis is 290,000 ± 10,000. Cardita hemoglobin contains one heme per 22,000 g protein. 5. 5. The amino acid composition of this pigment is presented.

New facts relating to the geology of the Paxos and Ionian zones, the outermost zones of the Hellenide structure of western Greece, are reported. In Leukas island, a shaly bituminous dolomite formation has been found to occur below the Cardita guembeli limestones which had previously been thought to be the oldest in Greece. In the eastern part of Cephallonia island there is evidence of transition between the Paxos and Ionian zones, represented principally by the extension of the limestone facies through the Oligocene and the presence of lower Miocene Flysch. The age of the gypsum found in the discordant upper Tertiary deposits is a problem; from their structural position and the nature of the associated limestone breccias, they could be Triassic or even Permian emplaced in two stages by a sort of diapirism.

The fossiliferous beds which form the subject of the following paper occupy positions at some distance from each other. The first and most interesting of them is situated in the neighbourhood of Pondicherry. The silicified wood, found in the adjacent sandstones, has long been known to the inhabitants of that part of the country, from the fine polish which it admits of and its capability of being formed into ornaments; but the beds of limestone which have furnished the material for the pavement for the streets of Pondicherry, and which lie within seven miles of the French capital in India, have almost entirely escaped observation. Pondicherry itself, as well as Madras, is situated on a very recent formation of loose sand, which extends for a considerable distance along the eastern coast of India, and which in many cases contains marine shells in such abundance that they are dug up and burnt for lime. I have obtained specimens from a spot about thirty miles from Pondicherry and ten from the coast. They are all shells such as now inhabit the Indian seas, and consist of—1. Pyrula vespertilio ; 2. Purpura carinifera ; 3. Cardita antiquata ; 4. Pullastra ; 5. an undescribed species of Cytherea ; 6. Arca granosa ; 7. Arca rhombea . This formation is usually bounded by granite, which comes to the surface at Sadras, Madras, and many other places along the coast. Immediately behind the town of Pondicherry, however, the recent beds rest upon some low hills of red sandstone, which encloses an

Borings and other types of shell damage are studied in the Pliocene Tielrode malacofauna. These investigations show that the Astarte species as well as a small Cardita lived directly under the sediment surface, and did not wander. The exact living positions of these four species could be determined; that of the Cardita was somewhat anomalous. Cyprina and Pygocardia lived on the sea bottom, as did Nassarius labiosus probably dwelt in the sand; Turritella triplicata lived lifetime. Nassarius labiosus probably dwelt in the sand; Turritella triplicata lived there also and was a prey for naticid snails and crabs. Polinices searched for food in the sediment, but was threatened by cannibalism and crustaceans. An estimate of the depletions caused by the latter could be made. The shell often served pagurid crabs, that carried Electra as principal epibiont on the shell. Neptunea and Thais lived exclusively on the sea bottom; only the shells of the latter were inhabited by hermit crabs, as the Neptunea is sinistrorsal. Both gastropods developed protecting shell layers against boring epibionts. In the introduction some examples are given of investigation of shell borings; the general features of the Tielrode deposit are described. In the discussion, possibilities and limitations of the method are dealt with.

In a former paper published in the Quarterly Journal of the Geological Society of London (vol. ii. p. 405, May 1846), I stated that the limestone containing abundantly the Nummulites Mantelli , Morton, which occurs near Suggesville, Clarksville, and other places between the rivers Alabama and Tombecbee, in the State of Alabama, was a member of the Eocene tertiary group, and that so far from constituting any part of the cretaceous formation, as had formerly been imagined, it holds in reality a place high up in the Eocene series of the South. In the same memoir I gave a section extending from Claiborne through Suggesville and Macon to the west of Clarksville, Alabama, in which the position of the so-called nummulitic limestone was explained. It was stated to be newer than all the beds of the well-known Claiborne Bluff, and I mentioned that “the bones of the gigantic cetacean called Zeuglodon by Owen were everywhere found in Clarke County, in a limestone below the level of the nummulitic rock and above the beds which contain the greater number of perfectly preserved eocene shells, such as Cardita planicosta and others.”

A Zurich-Montpellier analysis provided more detailed information about pelecypod associations in two sediment beds than either a traditional subjective approach or a cluster analysis based on Jaccard's coefficient. The Zurich-Montpellier test separated till and sand pelecypod associations, and indicated distinguishing species and atypical samples. Species distinguishing the till association were Cardita ventricosa, Yoldia myalis, Semele rubropicta, Venerupis kennerlyi, Clinocardium nuttallii, Nuculana minuta and Macoma incongrua. Species distinguishing the sand were Macoma elimata, Compsomyax subdiaphana, Yoldia ensifera, Macoma calcarea, M. lipara, M. brota, Yoldia limatula and Macoma alaskana. Two samples contained species from both associations plus some species rare elsewhere. Combined R-and Q-type grouping procedures, of which the Zurich-Montpellier approach is an example, are useful in evaluating benthic faunal similarities, but the suitability of various forms of the procedure needs further study.

I have lately visited, with my friend Escher von der Linth, the Alps of the Vorarlberg, and the neighbourhood of the Lake of Lugano and the Lake of Como. In the Vorarlberg we found immediately under the Lias, which is well developed, the beds of the Dachstein Limestone, characterized by numerous Corals and a large bivalve (Megalodon scutatus of Schafhautl, “Dachstein bivalve” of the Austrians). Below the Dachstein limestone are the Gervillia-beds (lately called Kossen-beds by Von Hauer). The Cardita crenata, Goldf., the Aviculae of the family of the Gryphaeatae, and small turrited univalves, contained in these beds, induced me to refer them to some of the St. Cassian beds. Lower still are thickly developed masses of dolomite, under which sandstones with impressions of Keuper plants occur. The exact relation of the Salzburg beds containing Ammonites globosus with the Gervillia-beds has not yet been made out. We have not hitherto been able to find in the Alps of the Vorarlberg this characteristic family of Ammonites. In the vicinity of the Lake of Como, the dolomitie masses change their appearance ; but beneath the lias the Gervillia-beds form a good geological horizon, which can be found in numerous places when once one has become accustomed to its position. This bed is also found under the Lias of the chain of the Stockhorn, Canton Berne ; and Escher has found it in the neighbourhood of Geneva. We have called the whole of the beds situated between the Lias and the Keuper

THE Deccan Traps comprise one of the largest volumes of basaltic volcanics known, covering an area of about 500,000 sq. km in western and central India. Their age and range of age have been the subjects of much debate in the past. In summing up the stratigraphic evidence for the age of the traps, Krishnan states1 that their base lies, in various places, on marine beds of Danian age (Cardita beaumonti beds), of Cenomanian to Senonian age (Bagh beds), and of roughly Turonian age (Lametas). Non-marine sediments within the Deccan Traps (Intertrappean beds) contain fossil plants and fish that are thought to be of Palaeocene age. In several places sediments overlying the traps are Palaeocene in age.

Mr. Hugh Cuming, the eminent conchologist, has lately received from Mr. F. Manse a small collection of fossils from two localities in the Middle Island of New Zealand. Though in a very bad state of preservation, they are sufficiently perfect to enable us to determine the genera, and to pronounce whether or not they are identical with or different from known New Zealand fossils, or animals now existing in the neighbouring seas. The one locality is at Banks9 river. The fossils are imbedded in a greenish grey sandstone. They consist of shells of the genera Solecurtus , one species; Tellina , one species; Lucina , three species; Cardita , one species; Artemis , one species; Pectunculus , one species; Crenella ? one large species; Modiola , coated with Membranipora ; Turritella , one species very abundant; Calyptrœa , one species; and Trochus , one species. The other locality is at the cliffs of Blind Bay. The fossils are imbedded in a greenish conglomerate of small pebbles. They consist of a Lucina , a large species of Area, a Cardita distinct from that at Banks9 river; one species of each of the following genera. Turbo, Fusus ? Acmœa, Bulla, Tornatella ? and a Haliotis -like shell; also two fragmentary corals, apparently belonging to the genera Turbinolia and Dendrophyllia . None of the fossils in either locality can be identified with any recent species. Their general aspect recalls very strongly that of eocene shells from the Bognor beds. The specimens have been presented by Mr. Cuming to the Museum of Practical Geology.