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Redescription of Halisarca dujardini type species (Figs. 2���23) Previous reviews. L��vi 1956; Bergquist 1996; Bergquist & Cook 2002. Halisarca dujardini Johnston, 1842 Synonymy. Halisarca dujardini Johnston, 1842: 192���193; Lendenfeld 1889: 729���730; de Laubenfels 1948: 175���176; L��vi 1956: 184; Chen 1976: 113���139; Ereskovsky 1993: 8; Bergquist 1996: 24���27; Bergquist & Cook 2002: 1090���1091. Halisarca franz-schulzei Merejkowsky 1878: 27���36, Pl. I, fig. 1���6; Pl. II, fig. 9���15. Hymeniacidon dujardini Bowerbank 1866: 224. Halisarca sputum Topsent 1893: 38 ���39. Original description. Halisarca dujardini, Johnston, 1842, p. 192. Type material. Holotype: presumably lost. Neotype: BMNH 1960.1.7.1���Black Rock, Brighton, English Channel (epizootic on algae, collected close to the type locality) (Bergquist & Cook 2002). Comparative material examined. Sponge specimens used in the revision of Halisarca dujardini were collected using SCUBA, in White Sea (Kandalaksha Bay, Chupa Inlet (66 �� 17 ' 32 "N ��� 33 �� 39 ' 39 "E), 3���5 m depth, from algae Fucus ramosus and Laminaria saccharina, July 2000���2004; in Barents Sea, Kola Peninsula, Dalnije Zelentsi (69 ��07' 19 "N ��� 36 ��03' 21 "E) 0.3���0.5 m depth, July, August 2003; in Bering Sea, Avacha Bay (52 �� 46 ' 32 "N ��� 158 �� 36 ' 16 "E) 10-11 m depth, October 18 2008; in Japan Sea the Gulf of Peter the Great near of the Marine Biological station ���Vostok��� (Marine Biological Institute of Russian Academy of Sciences) (42 �� 54 'N ��� 132 �� 38 'W) from rocks and boulders at a depth 0.4���4 m; in North Sea, Norway, Bergen (60 �� 23 ' 29 "N ��� 5 �� 13 ' 46 "E), June 2009, 6 m depth; in North Sea, Netherlands, Zeeland, Goese Sas (51 �� 38 ' 52 "N ��� 3 �� 48 '0"E) 18 m depth, July, 2009; NE Atlantic, North Wales (53 �� 14 ' 6 "N ��� 4 �� 7 ' 48 "W) July 1988, 3 m. We also investigated histologically a piece of the neotype and a piece of Halisarca franz-schulzei Merejkovsky, 1879 from Zoological Institute RAN, St-Petersburg, Russia. Description. External morphology. Predominantly incrusting sponge, 0.3���12 mm thick, forming smooth crusts on shallow water hard surfaces, or globular, 0.5���2 cm in diameter. Frequently a fouling organism (on red and brown algae, ascidians, shells of bivalves and brachiopods, tubes of sedentary polychaetes, hydroid stalks) (Figs. 2, 3). Incrusting forms have multiple oscula 0.3���1 mm in diameter, scattered regularly; globular sponges have one osculum or, occasionally, two oscula with raised rims, approximately 1���2 mm in diameter. Pores are dispersed. A significant reduction in the aquiferous system is characteristic for the latest phases of reproduction (embryo and larvae development). During these periods oscula and pores are rarely observed. Colour is yellow-beige to pale brown (Fig. 2); during last phases of reproduction the specimens have ivory or whitish colour due to the presence of embryos and larvae (Fig. 3). Surface is smooth and slimy. Consistency is soft, gelatinous and slightly elastic. Anatomy. Soft tissues. An ectosomal region up to 27 ��m thick, consists of three layers: (1) The upper layer composed of a mucous acellular cuticle 0.1���0.2 ��m thick (Figs. 4, 6), underlying external parts of T-shaped exopinacocytes and a diffuse collagen region 0.9���3 ��m thick beneath it; (2) the middle layer ~ 5���10 ��m thick containing interlaced collagen fibrils organized into firm tracts. This layer can include rare spherulous cells; and (3) the inner layer, up to 3���7 ��m thick, consisting of condensed collagen fibrils and the cell bodies of T-shape exopinacocytes. The choanosome makes up the greatest volume of the sponge body and is composed of choanocyte chambers, canals and mesohyl (Fig. 4). The organization of the aquiferous system is reminiscent of a syconoid system described earlier (L��vi 1956; Vacelet et al. 1989). The long, branching, tubular, meandering choanocyte chambers are arranged radially around a large exhalant canal (Fig. 4). Choanocyte chambers could vary in abundance and size depending on life cycle. During active growth period choanocyte chambers are 120���600 ��m long and 24���90 ��m in diameter. Abundance and length of choanocyte chambers decrease during reproduction (Fig. 5). Cytology. Choanocytes (Figs. 7, 8) are cylindrical or trapeziform, with long and numerous basal pseudopods (Vacelet et al. 1989; Boury-Esnault et al. 1990; Gonobobleva & Maldonado 2009). The cells are 6���9.5 ��m long and 3.5���5 ��m wide, with a smooth flagellum and a collar composed of 30���40 microvilli. Some but not all cells have a periflagellar asymmetrical cytoplasmic sleeve. Choanocytes within a choanocyte chamber are connected with each other at the basal-lateral surfaces with numerous interdigitations. Nuclei are pyriform (2.5 x 4.8 ��m) with apical thinning and often with one to three nucleoli. Cytoplasm contains phagosomes, electron transparent vacuoles, perinuclear Golgi complexes, and mitochondria. Exopinacocytes (Figs. 9���11) are T-shaped. External flat cytoplasmic parts connect with each other by interdigitations. Cell bodies, including the nucleus and the main cytoplasm volume, are situated beneath the ectosome. Cell bodies are connected with flat cytoplasmic parts by thin and long cytoplasmic bridges. Nuclei are nucleolated. Endopinacocytes (Figs. 12, 13) are flat fusiform or polygonal in shape. A nucleolated nucleus is oval, 1.6��� 2 x 3���3.8 ��m in size, and is located in the center of the cell. The cytoplasm includes well-developed Golgi complexes, small electron dense spherical inclusions and abundant electron-transparent vacuoles. Basopinacocytes (Figs. 14, 15) are flattened and polygonal, about 8���14 ��m in length and about 2 ��m in width. The cytoplasm includes a well-developed Golgi complex, small electron dense spherical inclusions and some phagosomes. Mesohylar cells. L��vi (1956) was the first to describe the free cells in the mesohyl of H. dujardini at light microscopy level. He distinguished three cells populations (types): (1) amoeboid or star-shaped cells with spherical central nucleus and clear cytoplasm containing small granules, called ���amoebocytes I and II���, or amoebocytes and collencytes; (2) the cells with the cytoplasm filled with acidophilic granules, called ���amoebocytes III���, or fuchsinophil cells, or granular cells; and (3) cells with large peripheral nucleus and the cytoplasm filled with big spherical inclusions ��� spherulous cells. In subsequent works (Bergquist 1996; Bergquist & Cook 2002) three types of mesohylar cells were also mentioned: (1) lophocytes; (2) spherulous cells, common in the zone between ectosome and choanosome and along canals; and (3) fuchsinophilic cells scattered throughout the choanosome. However, the use of electron microscopy led to recognition of six mesohylar cells types in H. dujardini: (1) amoebocytes, (2) collencytes or lophocytes, (3) spherulous cells, (4) granular cells, (5) microgranular cells, and (6) vacuolar cells (Volkova & Zolotareva 1981; Korotkova & Ermolina 1986; Sukhodolskaya & Krasukevitch, 1984), which are described below. (1) Archaeocytes (���amoebocytes I���) (Figs. 16, 17) are abundant cells in H. dujardini mesohyl. These cells have an irregular amoeboid shape and often produce pseudopodia. A large spherical nucleolated nucleus (2.5���3.5 ��m in diameter) is located in the center of the cell. Cytoplasm is characterized by the absence of any special or monotypical inclusions, although it can contain heterophagosomes and various osmiophilic or electron-transparent inclusions. There are well developed Golgi complex and endoplasmic reticulum. Archaeocytes are distributed throughout the mesohyl. (2) Lophocytes (Figs. 18, 19) have a star-like, clavate, or oval form, often with a tuft of secreted collagen fibrils attached to the lateral and posterior ends. The cytoplasm contains some phagosomes and small osmiophilic inclusions. An oval nucleolated nucleus is located in the anterior part of the cell. (3) Spherulous cells (Fig. 20) are oval or round in appearance (8���12 ��m in diameter) and are characterized by the presence in the cytoplasm of 2���7 large trapeziform, spherical, or oval homogenous osmiophilic inclusions 2���8 ��m in diameter. These inclusions have a microgranular structure. The cytosol is reduced to a thin layer between these inclusions. The cytoplasm sometimes contains large heterogenous inclusions and small electron transparent vacuoles. The Golgi complex is well developed. A nucleus without nucleoli could be in the cell���s center or at the periphery. Spherulous cells can be distributed anywhere in the mesohyl, but are more common in external parts of the choanosome. They often occupy the collagen-reinforced layer in the sponge ectosome. (4) Granular cells (amoebocytes III or fuchsinophilic cells) (Fig. 20) form one of the more numerous cell types in the mesohyl. The shape of these cells is highly variable; usually cells are irregular, ovoid or elongate with a mean diameter about 8 ��m. The cytoplasm is filed with round or oval electron-dense homogenous granules (0.5��� 2 ��m in diameter). The nucleus has a peripheral, or, rarely, central location in the cell. The cells are distributed throughout the choanosome. (5) Microgranular cells (Fig. 20). We propose to distinguish this cell type in H. dujardini from granular cells. Microgranular cells are characterized by irregular, amoeboid or, rarely, oval shape and have large lobopodia. The cytoplasm is filed with abundant small (0.2���0.5 ��m in diameter) electron-dense spherical or oval inclusions. These inclusions can be of oval shape or rod-shaped. The Golgi complex is well developed. The nucleus can be nucleolated or without nucleoli, located in the cell���s center or at the periphery. Microgranular cells do not display any special localization in the choanosome. (6) Vacuolar cells (Fig. 20) are rare in the mesohyl of H. dujardini but do not represent a stage in the ontogenesis of spherulous cell, as thought by L��vi (1956). Cells are irregular to oval in shape, 5 x 7���9 x 12 ��m in size. The cytoplasm contains one to 12 vacuoles of oval or elongated shape 0.5���7.2 ��m in diameter. Vacuoles are electrontransparent or could contain very loose mucus-like inclusions, and in sometimes intact symbiotic bacteria. Vacuolar cells are predominantly distributed in the middle part of the choanosome. Additional transient mesohylar cell types could differentiate at various stages in the life cycle. They can be nutritive cells, macrophages, and special granular cells containing cationic peptides and proteins. Nutritive cells (Fig. 21) are a mixed heterogeneous cell population with predominance of dedifferentiated choanocytes. Choanocytes filled with phagosomes leave choanocyte chambers and enter the mesohyl during oocytes vitellogenesis (Korotkova & Apalkova 1975; Korotkova & Aisenshtadt 1976; Aisenshtadt & Korotkova 1976). Among the nutritive cells there are also amoebocytes I and spherulous cells. Nutritive cells are phagocyted by growing oocytes for yolk granules formation. Macrophages (Fig. 22) are large cells that appear at the end of sexual reproduction when begins the postreproductive restoration phase of the life cycle (Ereskovsky 2000), or during the regeneration when it undergoes destructive processes in the mesohyl (Korotkova & Movchan 1973; Volkova & Zolotareva 1981; Korotkova & Ermolina 1986 b; Sukhodolskaya & Krasukevitch 1984). Cell dimensions can reach 30���35 ��m, the cytoplasm is filled with large heterogeneous phagosomes. A large spherical nucleus is nucleolated. Special eosinophilic granular cells (Fig. 23) contain cationic peptides and proteins (Krylova et al. 2004). These cells are amoeboid or oval in shape (about 8���12 ��m in diameter); the nucleus is oval and voluminous (about 3.2 ��m in diameter) with condensed heterochromatin or a small nucleolus. The cytoplasm contains several specific inclusions: (1) vacuoles that include one to ten round or oval electron-dense granules with peripheral thinly-fibrillar material; (2) vacuoles with electron-dense fine-granular inclusions; (3) electron-dense thinly-fibrillar inclusions located in the cytoplasm. Cells differentiate at the beginning of vitellogenesis of oocytes. During the embryonic development they concentrate in the mesohyl surrounding embryos. These eosinophilic granular cells (or eosinophilic amoebocytes) of maternal sponge penetrate developing embryos and remain there until the beginning of metamorphosis (Korotkova & Ermolina 1982; Ereskovsky & Gonobobleva 2000; Gonobobleva & Ereskovsky 2004 a, b). Symbiotic bacteria. Symbiotic bacteria of H. dujardini are represented by a single morphotype found both in the mesohyl of all investigated adults (Fig. 20) and during all stages of embryonic development of the White Sea specimens (Ereskovsky et al. 2005). Bacteria are almost evenly distributed in the mesohyl and do not form accumulations. Sometimes bacteria are located in vacuoles of archaeocytes. Bacteria (likely gram-positive) have a curved spiral form, characteristic of spirills (Fig. 20). Their length is about 0.45 ��m, thickness 0.18 ��m, the cell wall is 0.05 ��m thick. No flagella or piles are found at the surface of bacterial wall. The cytoplasm is heterogeneous. Its peripheral part has a medium electronic density, while the central part is electron dense and possibly corresponds to the nucleoid. In-between, a thin electron-transparent layer is visible. Reproduction. The sponge is dioecious (however some rare individuals could be hermaphrodites) with short seasonal period of reproduction (Table 2). Spermatogenesis occurs only during the cold part of the year (Ereskovsky 2000). Larvae are sub-spherical to oval dispherulae, 100���200 ��m in diameter, completely ciliated but only sparsely so at the posterior pole (Ereskovsky & Gonobobleva 2000; Gonobobleva & Ereskovsky 2004 a, b). Habitat. Halisarca dujardini is usually found at depths from 1 to 20 m but also from upper littoral (Barents Sea) to 300 m (Skagerrak), mainly on the algae Fucus vesiculosus, F. serratus, Ascophyllum nodosum and Laminaria saccharina, under and on stones and boulders, in empty shells of lamellibranchs, on carapaces of crabs, at the base of gorgonians, and on the ascidian Styela rustica. Distribution. Halisarca dujardini species complex is considered to be cosmopolitan (Bergquist & Cook 2002). In fact, however, its distribution is limited to temperate waters: in the North Atlantic���along the European costs from English Channel to White Sea and in Atlantic coast of USA (Massachusetts) and in the North-West of Mediterranean Sea; in North Pacific���Bering Sea, Avacha Bay and in Russian coast of Japan Sea; in South Pacific���the New Zealand coasts (Fig. 24). See Annex 1 for the detailed distribution. Material examined. Holotype: collected in ���Grotte �� Corail��� Maire Island, 16 m depth, 43 �� 12 ' 38.04 "N ��� 5 �� 19 ' 56.80 "E, Mus��um National d'Histoire Naturelle (Paris, France) MNHN DJV 128. Paratype: collected in ���Grotte �� Corail��� Maire Island, 16 m depth, 43 �� 12 ' 38.04 "N ��� 5 �� 19 ' 56.80 "E, Zoological Institute RAS (Saint-Petersburg, Russia) № 11141. Description. External morphology. Thinly incrusting sponge, 0.17���0.19 mm thick, spreading on the surface of the living bryozoan Smittina cervicornis (Fig. 25, 26). The sponge covers the host���s colony from the base to the tips of the branches with a continuous layer. Most often, the sponge coating is very thin and transparent, and thus hardly visible. The sponge may become relatively thick and then appears as an opaque sheath. The surface is skinlike, lustreless and smooth, even (Fig. 26). Oscula have a cone shape (height: 0.1���0.5 ��m and diameter about 0.5 mm) and are located exclusively along the bryozoan branch edges that are devoid of zooid orifices. Texture is soft, very delicate and easily torn. The colour is pale-yellow. Internal organization. Soft tissue organization. There is a thin ectosomal region, 4���14 ��m deep, consisting of the flat part of exopinacocytes and of an underlying dense collagen layer, about 1.7���2.6 ��m deep (Fig. 27). This layer contains symbiotic bacteria and some secretory cells (Fig. 27). Cell bodies of T-shape exopinacocytes and rare spherulous cells occur beneath the collagen layer. The choanosome makes up most of the volume of the sponge body and is composed of choanocyte chambers and mesohyl (Figs. 27, 28). The individual choanocyte chambers are tubular in shape, sometimes branched, measuring from 76 up to 175 ��m in length and are 9.3���14 ��m wide. There are mobile cells present in the mesohyl. The basal part (Fig. 29), in contact with the bryozoan surface, includes a dense, thin (0.17 ��m) cuticle secreted by the basopinacocytes. Collagen cuticle includes spiral symbiotic bacteria and other bacteria, which are not present in other sponge parts. Cytology. Exopinacocytes (Fig. 30) are T-shaped with a thin, flattened external cytoplasmic part, and an internal cell body. The cell body is irregular or triangular in shape, about 4.9 x 5.3 ��m. The two parts of the cell are connected by a thin cytoplasmic bridge. Nucleus is lightly ovoid (2.2���2.4 ��m in diameter), often without nucleolus. Choanocytes (Fig. 28, 31) are elongate or roughly pyramidal, 2.3���5.3 ��m wide at the base and 1.9���4.2 ��m wide at the nucleus area, the height is 4���5.9 ��m. Choanocyte collar arises at approximately 4 / 5 of the height of the cell and is composed of about 18 microvilli. Nucleus is central or apical, spherical about 1.9 ��m in diameter, occasionally with a nucleolus, 0.5 ��m in diameter. The apical part of choanocytes encompasses many small vacuoles. The central and basal cytoplasm usually contains 2���4 phagosomes, 0.8���1.5 ��m in diameter with heterogeneous inclusions. The choanocytes also contain mitochondria, osmiophilic granules (0.3���0.6 ��m), electron transparent vacuoles (0.1���0.8 ��m) and other inclusions. The choanocytes contact each other only at the base. Long fine pseudopodia frequently arise from the central and basal parts of the choanocytes; the latter anchor choanocytes in the mesohyl. The free apical surface of the choanocytes and the flagella are covered by a thin (1 ��m) glycocalyx layer. Endopinacocytes (Fig. 32), Published as part of Ereskovsky, Alexander V., Lavrov, Dennis V., Boury-Esnault, Nicole & Vacelet, Jean, 2011, Molecular and morphological description of a new species of Halisarca (Demospongiae: Halisarcida) from Mediterranean Sea and a redescription of the type species Halisarca dujardini, pp. 5-31 in Zootaxa 2768 on pages 10-25, DOI: 10.5281/zenodo.206842, {"references":["Levi, C. (1956) Etude des Halisarca de Roscoff. Embryologie et systematique des demosponges. Archives de Zoologie experimentale et generale, 93, 1 - 184.","Bergquist, P. R. (1996) The marine fauna of New Zealand. Porifera, Class Demospongiae. Part 5: Dendroceratida & Halisarcida. Memoirs of the New Zealand Oceanographic Institute, 107, 1 - 53.","Bergquist, P. R. & Cook, S. C. (2002) Order Halisarcida Bergquist, 1996. In: Hooper, J. N. A. & Soest van, R. W. M. (Eds.), Systema Porifera: A guide to the classification of sponges, Kluwer Academic / Plenum Publishers, New York, pp. 1089.","Johnston, G. (1842) A history of British sponges and lithophytes. Lizard, WH, Edinburgh, 264 pp.","Lendenfeld, R. von (1889) A monograph of the Horny Sponges. Trubner and Co, Ludgate Hill, EC, London, 936 pp.","Laubenfels, M. W. de (1948) The order Keratosa of the phylum Porifera. A monographic study. Allan Hancock Foundation Publications Occasional Paper, 3, 1 - 217.","Chen, W. T. (1976) Reproduction and speciation in Halisarca. In: Harrison, F. W. & Cowden, R. R. (Eds.), Aspects of sponge biology, Academic Press, New York, pp. 113 - 140.","Ereskovsky, A. V. (1993) Addition to the fauna of sponges (Porifera) of the White Sea. Vestnik of St-Petersburg University, 2, 3 - 12.","Merejkowsky, C. D. (1878) Les eponges de la mer Blanche. Memoires de l'Academie imperiales des Sciences de St Petersbourg, 26, 1 - 51.","Bowerbank, J. S. (1866) A monograph of the British Spongiadae. Robert Hardwicke, London, 388 pp.","Topsent, E. (1893) Nouvelle serie de diagnoses d'eponges de Roscoff et de Banyuls Archives de Zoologie experimentale et generale, 1, 33 - 43.","Vacelet, J., Boury-Esnault, N., De Vos, L. & Donadey, C. (1989) Comparative study of the choanosome of Porifera: II. The Keratose Sponges. Journal of Morphology, 201, 119 - 129.","Boury-Esnault, N., De Vos, L., Donadey, C. & Vacelet, J. (1990) Ultrastructure of choanosome and sponge classification. In: Rutzler, K. (Ed.), New Perspectives in Sponge Biology, Smithsonian Institution Press, Washington, pp. 237 - 244.","Gonobobleva, E. L. & Maldonado, M. (2009) Choanocyte ultrastructure in Halisarca dujardini (Demospongiae, Halisarcida).","Volkova, M. A. & Zolotareva, G. A. (1981) The development of Halisarca dujardini Johnston from conglomerates of somatic cells. In: Korotkova, G. P., (Ed.), Morphogenesis in sponges, Leningrad University Press, Leningrad, pp. 74 - 92.","Sukhodolskaya, A. N. & Krasukevitch, T. N. (1984) The effect of inozine on the development of Halisarca dujardini from small fragments of the body. Vestnik of Leningrad University, 3, 56 - 62.","Korotkova, G. P. & Apalkova, L. V. (1975) Oogenesis of the Barents Sea sponge Halisarca dujardini Johnston. In: Tokin, B. P., (Ed.), Comparative and experimental morphology of the sea organisms, Kola Filial Academy of Sciences USSR Press, Murmansk, pp. 9 - 26.","Korotkova, G. P. & Movchan N. A. (1973) The peculiarities of defensive-regenerational processes of the sponge Halisarca dujardini. Vestnik Leningradskogo Universiteta, 21, 16 - 25.","Korotkova, G. P. & Ermolina, N. O. (1986 b) Destruction of embryos during the reproductive period in the White Sea sponge Halisarca dujardini Johnston (Demospongiae). Vestnik Leningradskogo Universiteta (Biologia), 4, 104 - 106.","Krylova, D. D., Aleshina, G. M., Kokryakov, V. N. & Ereskovsky, A. V. (2004) Antimicrobal propeties of mesohylar granular cells of Halisarca dujardini Johnston, 1842 Demospongiae, Halisarcida). In: Pansini, M., Pronzato, R., Bavestrello, G., & Manconi, R., (Eds.), Sponge science in the new millennium. Bollettino dei Musei e degli Instituti Biologici dell' Universita di Genova, 68, pp. 399 - 404.","Korotkova, G. P. & Ermolina, N. O. (1982) The larval development of Halisarca dujardini (Demospongiae). Zoological Journal, 61, 1472 - 1480.","Ereskovsky, A. V. & Gonobobleva, E. L. (2000) New data on embryonic development of Halisarca dujardini Johnston, 1842 (Demospongiae, Halisarcida). Zoosystema, 22, 355 - 368.","Gonobobleva, E. L. & Ereskovsky, A. V. (2004 a) Metamorphosis of the larva of Halisarca dujardini (Demospongiae, Halisarcida). Bulletin de l'Institut royal des Sciences naturelles de Belgique, Biologie, 74, 101 - 115.","Gonobobleva, E. L. & Ereskovsky, A. V. 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(2008) Reconstructing ordinal relationships in the Demospongiae using mitochondrial genomic data. Molecular Phylogeneny and Evolution, 49, 111 - 124."]}

Bajalus Lendenfeld, 1885 Diagnosis. Halisarcida in which the choanocyte chambers are tubular, branched, and wide mouthed. Larvae are incubated dispherulae (a larval form found only in Halisarca) with simple undifferentiated histology and cilia of uniform length. Skeleton is composed of fibrillar collagen only, there are no fibrous or mineral elements present; ectosomal and subectosomal collagen is highly organised and structurally diversified (modified from Bergquist & Cook 2002). Type species: Halisarca dujardini Johnston, 1842: 192., Published as part of Ereskovsky, Alexander V., Lavrov, Dennis V., Boury-Esnault, Nicole & Vacelet, Jean, 2011, Molecular and morphological description of a new species of Halisarca (Demospongiae: Halisarcida) from Mediterranean Sea and a redescription of the type species Halisarca dujardini, pp. 5-31 in Zootaxa 2768 on page 10, DOI: 10.5281/zenodo.206842, {"references":["Bergquist, P. R. & Cook, S. C. (2002) Order Halisarcida Bergquist, 1996. In: Hooper, J. N. A. & Soest van, R. W. M. (Eds.), Systema Porifera: A guide to the classification of sponges, Kluwer Academic / Plenum Publishers, New York, pp. 1089.","Johnston, G. (1842) A history of British sponges and lithophytes. Lizard, WH, Edinburgh, 264 pp."]}