Spongilla fragilis, Leidy, P. Ac. Philad. 1851, p. 278.Spongilla lordii, Bowerbank, P. Zool. Soc. London, 1863, p. 466, pl. xxxviii, fig. 17.Spongilla contecta, Noll, Zool. Garten*, 1870, p. 173.Spongilla ottavænsis, Dawson, Canad. Nat.* (new series) viii, p. 5 (1878).Spongilla sibirica, Dybowski, Zool. Anz., Jahr. i, p. 53 (1878).Spongilla morgiana, Potts, P. Ac. Philad. 1880, p. 330.Spongilla lordii, Carter, Ann. Nat. Hist. (5) vii, p. 89, pl. vi, fig. 13 (1881).Spongilla sibirica, Dybowski, Mém. Ac. St. Pétersb. (7) xxx, no. x, p. 10, fig. 12.Spongilla glomerata, Noll, Zool. Anz., Jahr. ix, p. 682 (1886).Spongilla fragilis, Vejdovsky, P. Ac. Philad. 1887, p. 176.Spongilla fragilis, Potts,ibid.p. 197, pl. v, fig. 2; pl. viii, figs. 1-4.Spongilla fragilis, Weltner, Arch. Naturg. lix (1), p. 266, pl. ix, figs. 18-20 (1893).Spongilla fragilis,id., Arch. Naturg. lxi (i), p. 117 (1895).Spongilla fragilis,id., in Semon's Zool. Forsch. in Austral. u. d. Malay. Arch. v, part v, p. 523.Spongilla fragilis, Annandale, P. U.S. Mus. xxxvii, p. 402 (1909).Spongilla fragilis,id., Annot. Zool. Japon. vii, part ii, p. 106, pl. ii, fig. 1 (1909).
Spongeflat, lichenoid, never of great thickness, devoid of branches, dense in texture but very friable; colour brown, green, or whitish; oscula numerous, small, flat, distinctly star-shaped.
Skeletonwith well defined radiating and transverse fibres, which are never strong but form a fairly dense network with a small amount of spongin.
Spicules.Skeleton-spicules smooth, sharply pointed, moderately stout, as a rule nearly straight. No flesh-spicules. Gemmule-spicules cylindrical, blunt or abruptly pointed, nearly straight, covered with relatively stout, straight, irregular spines, which are equally distributed all over the spicule.
Gemmulesbound together in free groups of varying numbers and forming a flat layer at the base of the sponge; each gemmule small in size, surrounded by a thick cellular coat of several layers; with a relatively long and stout foraminal tubule, which projects outwards through the cellular coat at the sides of the group or at the top of the basal layer of gemmules, is usually curved, and is not thickened at the tip; more than one foraminal tubule sometimes present on a single gemmule; gemmule-spicules arranged horizontally or at the base of the cellular coat.
The species as a species is easily distinguished from all others, its nearest ally being the N. AmericanS. ingloriformiswith sparsely spined skeleton-spicules which are very few in number, and gemmule groups in which the foraminal tubules all open downwards.
Several varieties ofS. fragilishave been described in Europe and America.
Type.—Potts refers to the type as being in the Academy of Natural Sciences at Philadelphia.
Geographical Distribution.—All over Europe and N. America; also in Siberia, Australia, and S. America. The species is included in this work in order that its Asiatic local races may be fitly described.
9a.Subsp.calcuttana*, nov.
?Spongilla decipiens, Weltner (partim), Arch. Naturg. lxi (i), pp. 117, 134 (1895).Spongilla decipiens, Annandale, Journ. As. Soc. Beng. 1906, p. 57.Spongilla fragilis,id., Rec. Ind. Mus. i, p. 390 (1907).
Illustration: Fig. 15.—Spongilla fragilis subsp. calcuttana. A=group of gemmules, × 70; B=spicules, × 240. From type specimen.Fig. 15.—Spongilla fragilissubsp.calcuttana. A=group of gemmules, × 70; B=spicules, × 240. From type specimen.
Fig. 15.—Spongilla fragilissubsp.calcuttana. A=group of gemmules, × 70; B=spicules, × 240. From type specimen.
This local race, which is common in Calcutta, is distinguished from the typical form mainly by the shape of its skeleton-spicules, most of which are abruptly pointed or almost rounded atthe tips, sometimes bearing a minute conical projection at each end. The gemmule-spicules, which are usually numerous, are slender. The foraminal tubules are usually long and bent, but are sometimes very short and quite straight. The colour is usually greyish, occasionally brown.
I have not found this race except in Calcutta, in the ponds of which it grows on bricks or, very commonly, on the stems of bulrushes, often covering a considerable area.
Typein the Indian Museum.
9b.Subsp.decipiens*,Weber.
Spongilla decipiens, Weber, Zool. Ergeb. Niederländ. Ost-Ind. i, p. 40, pl. iv, figs. 1-5 (1890).
This (?) local race is distinguished by the fact that the foraminal tubules are invariably short and straight and thickened at the tips, and that gemmule-spicules do not occur on the external surface of the cellular coat of the gemmules.
I include Weber'sSpongilla decipiensin the Indian fauna on the authority of Weltner, who identified specimens from the Museum "tank," Calcutta, as belonging to this form. All, however, that I have examined from our "tank" belong to the subspeciescalcuttana, most of the skeleton-spicules of which are much less sharp than those ofdecipiens. By the kindness of Prof. Max Weber I have been able to examine a co-type of his species, which is probably a local race peculiar to the Malay Archipelago.
Typein the Amsterdam Museum; a co-type in Calcutta.
Perhaps the Japanese form, which has spindle-shaped gemmule-spicules with comparatively short and regular spines, should be regarded as a third subspecies, and the Siberian form as a fourth.
10.Spongilla gemina*, sp. nov.
Spongeforming small, shallow, slightly dome-shaped patches of a more or less circular or oval outline, minutely hispid on the surface, friable but moderately hard. Oscula numerous but minute and inconspicuous, never star-shaped. Dermal membrane adhering closely to the sponge. Colour grey or brown.
Skeletonforming a close and regular network at the base of the sponge, becoming rather more diffuse towards the external surface; the radiating and the transverse fibres both well developed, of almost equal diameter. Little spongin present.
Spicules.Skeleton-spicules slender, smooth, sharply pointed. No flesh-spicules. Gemmule-spicules long, slender, cylindrical, blunt or bluntly pointed, somewhat irregularly covered with minute straight spines.
Gemmulessmall, bound together in pairs, as a rule free in the parenchyma but sometimes lightly attached at the base of the sponge. Each gemmule flattened on the surface by which it is attached to its twin, covered with a thin coat of polygonal air-spaces which contains two layers of gemmule-spicules crossing one another irregularly in a horizontal plane. One or two foraminaltubules present on the surface opposite the flat one, bending towards the latter, often of considerable length, cylindrical and moderately stout.
Typein the Indian Museum.
This species is closely allied toS. fragilis, from which it may be distinguished by the curious twinned arrangement of its gemmules. It also differs fromS. fragilisin having extremely small and inconspicuous oscula.
Locality.I only know this sponge from the neighbourhood of Bangalore, where Dr. Morris Travers and I found it in October, 1910 growing on stones and on the leaves of branches that dipped into the water at the edge of a large tank.
11.Spongilla crassissima*,Annandale.
Spongilla crassissima, Annandale, J. Asiat. Soc. Bengal, 1907, p. 17, figs. 2, 3.Spongilla crassissima,id.,ibid.p. 88.Spongilla crassissima,id., Rec. Ind. Mus. i. p. 390, pl. xiv, fig. 4 (1907).
Spongevery hard and strong, nearly black in colour, sometimes with a greenish tinge, forming spherical, spindle-shaped or irregular masses without branches but often several inches in diameter. Oscula circular or star-shaped, usually surrounded by radiating furrows; pores normally contained in single cells. External membrane closely adherent to the sponge except immediately round the oscula.
Skeletondense, compact and only to be broken by the exercise of considerable force; radiating and transverse fibres not very stout but firmly bound together by spongin (fig. 6, p. 38), which occasionally extends between them as a delicate film; their network close and almost regular.
Spicules.Skeleton-spicules smooth, feebly curved, sausage-shaped but by no means short, as a rule bearing at each end a minute conical projection which contains the extremity of the axial filament. No flesh-spicules. Gemmule-spicules closely resembling those ofS. fragilissubsp.calcuttana, but as a rule even more obtuse at the ends.
Gemmulesas inS. fragilissubsp.calcuttana; a basal layer of gemmules rarely formed.
11a.Var.crassior*,Annandale.
Spongilla crassior, Annandale, Rec. Ind. Mus. i, p. 389, pl. xiv, fig. 3 (1907).
This variety differs from the typical form chiefly in its even stronger skeleton (fig. 3, p. 33) and its stouter skeleton-spicules, which do not so often possess a terminal projection. The sponge is of a brownish colour and forms flat masses of little thickness but of considerable area on sticks and on the stems of water-plants.
Types.—The types of both forms are in the Indian Museum. Co-types have been sent to London.
Geographical Distribution.—This sponge is only known from Bengal. The varietycrassiorwas found at Rajshahi (Rampur Bhulia) on the Ganges, about 150 miles N. of Calcutta, while the typical form is fairly common in the "tanks" of Calcutta and very abundant in the Sur Lake near Puri in Orissa.
Illustration: Fig. 16.—Spicules of Spongilla crassissima var. crassior (from type specimen), × 240.Fig. 16.—Spicules ofSpongilla crassissimavar.crassior(from type specimen), × 240.
Fig. 16.—Spicules ofSpongilla crassissimavar.crassior(from type specimen), × 240.
Biology.—S. crassissimais usually found near the surface in shallow water. Attached to the roots of the floating water-plantPistia stratiotesit assumes a spherical form, while on sticks or like objects it is spindle-shaped. Sometimes it is found growing on the same stick or reed-stem asS. carteri, the two species being in close contact andS. carterialways overlappingS. crassissima. The dark colour is due to minute masses of blackish pigment in the cells of the parenchyma. The dense structure of the sponge is not favourable to the presence ofincolæ, but young colonies of the polyzoonPlumatella fruticosaare sometimes overgrown by it. Although they may persist for a time by elongating their tubular zoœcia through the substance of the sponge, they do not in these circumstances reach the same development as when they are overgrown by the much softerS. carteri.
S. crassissimais found during the "rains" and the cold weather. In Calcutta it attains its maximum size towards the end of the latter season. In spite of its hard and compact skeleton, the sponge does not persist from one cold weather to another.
A curious phenomenon has been noticed in this species, but only in the case of sponges living in an aquarium, viz. the cessation during the heat of the day of the currents produced by its flagella.
Subgenus C.STRATOSPONGILLA,Annandale.
Stratospongilla, Annandale, Zool. Jahrb., Syst. xxvii, p. 561 (1909).
Type,Spongilla bombayensis, Carter.
Spongillæ in the gemmules of which the pneumatic layer is absent or irregularly developed, its place being sometimes taken by air-spaces between the stout chitinous membranes that cover the gemmule. At least one of these membranes is always present.
The gemmule-spicules lie in the membrane or membranes parallel to the surface of the gemmule, and are often so arranged as to resemble a mosaic. The gemmules themselves are usually adherent to the support of the sponge. The chitinous membrane or membranes are often in continuity with a membrane that underlies the base of the sponge. The skeleton is usually stout, though often almost amorphous, and the skeleton-spicules are sometimes sausage-shaped.
Sponges of this subgenus form crusts or sheets on solid submerged objects.
Stratospongillais essentially a tropical subgenus, having its head-quarters in Central Africa and Western India. One of its species, however, (S. sumatrana*, Weber) occurs both in Africa and the Malay Archipelago, while another has only been found in S. America (S. navicella, Carter).
Aberrant species occur in China (S. sinensis*,S. coggini*) and the Philippines (S. clementis*). Three species have been found in the Bombay Presidency and Travancore, one of which (S. bombayensis*) extends its range eastwards to Mysore and westwards across the Indian Ocean to Natal.
12.Spongilla indica*,Annandale.
Spongilla indica, Annandale, Rec. Ind. Mus. ii, p. 25, figs. 1, 2 (1908).
Spongeforming a very thin layer, of a bright green or pale grey colour; surface smooth, minutely hispid; pores and oscula inconspicuous, the latter approached in some instances by radiating furrows; subdermal cavity small; texture compact, rather hard.
Skeletonincoherent, somewhat massive owing to the large number of spicules present. Spicules forming triangular meshes and occasionally arranged in vertical lines several spicules broad but without spongin.
Spicules.Skeleton-spicules straight or nearly straight, slender, cylindrical, amphistrongylous, uniformly covered with minute, sharp spines; flesh-spicules slender, sharply pointed, straight or curved, irregularly covered with relatively long, straight sharp spines, abundant in the dermal membrane, scarce in the substanceof the sponge. Gemmule-spicules short, stout, sausage-shaped, covered with minute spines, which are sometimes absent from the extremities.
Gemmulesspherical, somewhat variable in size, with a single aperture, which is provided with a trumpet-shaped foraminal tubule and is situated at one side of the gemmule in its natural position; the inner chitinous coat devoid of spicules, closely covered by an outer coat composed of a darkly coloured chitinoid substance in which the gemmule-spicules are embedded, lying parallel or almost parallel to the inner coat. The outer coat forms a kind of mantle by means of the skirts of which the gemmule is fastened to the support of the sponge. This coat is pierced by the foraminal tubule. The gemmules are distinct from one another.
Illustration: Fig. 17.—Gemmule of Spongilla indica seen from the side (from type specimen), magnified.Fig. 17.—Gemmule ofSpongilla indicaseen from the side (from type specimen), magnified.
Fig. 17.—Gemmule ofSpongilla indicaseen from the side (from type specimen), magnified.
S. indicais closely allied toS. sumatrana*, Weber, which has been found both in the Malay Archipelago and in East Africa. It may be distinguished by its blunt, almost truncated megascleres and comparatively slender gemmule-spicules.
Typein the Indian Museum.
Habitat, etc.—Growing, together withS. cinereaandCorvospongilla lapidosa, on the stone sides of an artificial conduit in the R. Godaveri at Nasik on the eastern side of the Western Ghats in the Bombay Presidency. The water was extremely dirty and was used for bathing purposes. The sponge was green wherethe light fell upon it, grey where it was in the shadow of the bridge under which the conduit ran. The only specimens I have seen were taken in November, 1907.
13.Spongilla bombayensis*,Carter. (Plate II, fig. 2.)
Spongilla bombayensis, Carter, Ann. Nat. Hist. (5) x, p. 369, pl. xvi, figs. 1-6 (1882).Spongilla bombayensis, Annandale, Zool. Jahrb., Syst. xxvii, p. 562, figs. B, C (1909).
Spongehard but friable, forming thin layers or cushions; its surface often irregular but without a trace of branches; its area never very great; oscula inconspicuous; external membrane adhering closely to the sponge; colour brownish or greyish.
Illustration: Fig. 18.—Gemmule of Spongilla bombayensis as seen from above (from type specimen), magnified.Fig. 18.—Gemmule ofSpongilla bombayensisas seen from above (from type specimen), magnified.
Fig. 18.—Gemmule ofSpongilla bombayensisas seen from above (from type specimen), magnified.
Skeletonalmost amorphous, very dense, consisting of large numbers of spicules arranged irregularly; radiating fibres occasionally visible in sections, but almost devoid of spongin; a more or less definite reticulation of horizontal spicules lying immediately under the external membrane.
Spicules.Skeleton-spicules slender, pointed, feebly curved, irregularly roughened or minutely spined all over the surface. Flesh-spicules straight, narrowly rhomboidal in outline, sharply pointed, slender, covered with minute, irregular, straight spines, scanty in the parenchyma, abundant in the external membrane. Gemmule-spicules sausage-shaped or bluntly pointed, variable in length but usually rather stout, covered with minute spines, as a rule distinctly curved.
Gemmulesround or oval, firmly adherent[AH]to the base of the sponge, as a rule rather shallowly dome-shaped, covered by twothick chitinous membranes, in each of which there is a dense horizontal layer of spicules; no granular or cellular covering; the two chitinous coats separated by an empty space; the aperture or apertures on the side of the gemmule in its natural position, provided with foraminal tubules, which may be either straight or curved, project through the outer chitinous membrane and often bend down towards the base of the gemmule. The spicules of the outer layer often more irregular in outline and less blunt than those of the inner layer.
This sponge is allied toS. indica, but is distinguished among other characters by its sharp skeleton-spicules and by the fact that the gemmule is covered by two chitinous membranes instead of one.
Typein the British Museum; a fragment in the Indian Museum.
Geographical Distribution.—S. and W. India and S. Africa. Carter's type was found in the island of Bombay, my own specimens in Igatpuri Lake in the Western Ghats. I have recently (October 1910) found sponges and bare gemmules attached to stones at the end of a tank about 10 miles from Bangalore (Mysore State) in the centre of the Madras Presidency. Prof. Max Weber obtained specimens in Natal.
Biology.—The specimens collected by Prof. Weber in Natal and those collected by myself in the Bombay Presidency were both obtained in the month of November. It is therefore very interesting to compare them from a biological point of view. In so doing, it must be remembered that while in S. Africa November is near the beginning of summer, in India it is at the beginning of the "cold weather," that is to say, both the coolest and the driest season of the year. The lake in which my specimens were obtained had, at the time when they were collected, already sunk some inches below its highest level, leaving bare a gently sloping bank of small stones. Adhering to the lower surface of these stones I found many small patches ofSpongilla bombayensis, quite dry but complete so far as their harder parts were concerned and with the gemmules fully formed at their base. From the shallow water at the edge of the lake I took many similar stones which still remained submerged. It was evident that the sponge had been just as abundant on their lower surface as on that of the stones which were now dry; but only the gemmules remained, sometimes with a few skeleton-spicules adhering to them (Pl. II, fig. 2). The bulk of the skeleton had fallen away and the parenchyma had wholly perished. In a few instances a small sponge, one or two millimetres in diameter, had already been formed among the gemmules; but these young sponges appeared to belong to some other species, possiblySpongilla indica, which was also common in the lake.
Carter's specimen ofS. bombayensis, which was evidently in much the same condition as those I found still submerged amonth later, was taken in October in a disused quarry. It was surrounded by a mass ofS. carterithree inches in diameter, and was attached to a herbaceous annual. The point on the edge of the quarry at which this plant grew was not reached by the water until July. It is therefore necessary to assume that the gemmules ofS. bombayensishad been formed between July and October. Probably the larva of the sponge had settled down on the plant during the "rains"—which commence in Bombay about the beginning of June—and had grown rapidly. The production of gemmules may have been brought about owing to the sponge being choked by the more vigorous growth ofS. carteri, a species which grows to a considerable size in a comparatively short time, whileS. bombayensisapparently never reaches a thickness of more than a few millimetres.
The manner in which the gemmules ofS. bombayensisare fastened to the solid support of the sponge must be particularly useful in enabling them to sprout in a convenient environment as soon as the water reaches them. The fact that the gemmules remained fixed without support renders it unnecessary for the skeleton to persist as a cage containing them (or at any rate a proportion of them) during the period of rest.
Prof. Weber's specimens ofS. bombayensiswere collected in a river, apparently on stones or rocks, towards the beginning of the S. African summer. They contain comparatively few gemmules and were evidently in a vigorous condition as regards vegetative growth. Unfortunately we know nothing of the seasonal changes which take place in freshwater sponges in S. Africa, but the difference between these changes in Europe and in India shows that they are dependent on environment as well as the idiosyncrasy of the species. It is very interesting, therefore, to see that the condition of sponges taken in S. Africa differs so widely from that of other individuals of the same species taken in India at the same season.
In Prof. Weber's specimens I have found numerous small tubules of inorganic débris. These appear to be the work of Chironomid larvæ, of which there are several specimens loose in the bottle containing the sponges. Other tubules of a very similar appearance but with a delicate chitinoid foundation appear to be the remains of a species ofPlumatellaof which they occasionally contain a statoblast.
14.Spongilla ultima*,Annandale. (Plate II, fig. 3.)
Spongilla ultima, Annandale, Rec. Ind. Mus. v, p. 31 (1910).
Spongehard and strong, forming a thin layer on solid objects, of a pale green colour (dry); the oscula small but rendered conspicuous by the deep radiating furrows that surround them; external surface of the sponge rough but not spiny.
Skeletonforming a compact but somewhat irregular reticulation in which the radiating fibres are not very much more distinct than the transverse ones; a considerable amount of almost colourless spongin present.
Spicules.Skeleton-spicules smooth, stout, amphioxous, as a rule straight or nearly straight, not infrequently inflated in the middle or otherwise irregular. No flesh-spicules. Gemmule-spicules variable in size, belonging to practically every type and exhibiting practically every abnormality possible in the genus, the majority being more or less sausage-shaped and having a roughened surface, but others being cruciform, spherical, subspherical, rosette-like, needle-like, bifid or even trifid at one extremity.
Illustration: Fig. 19.—Spicules of Spongilla ultima (from type specimen), × 120.Fig. 19.—Spicules ofSpongilla ultima(from type specimen), × 120.
Fig. 19.—Spicules ofSpongilla ultima(from type specimen), × 120.
Gemmulesadherent, spherical, large, each covered by two distinct layers of horizontal spicules; the outer layer intermixed with skeleton-spicules and often containing relatively large siliceous spheres, a large proportion of the spicules being irregular in shape; the spicules of the inner layer much more regular and as a rule sausage-shaped. The outer layer is contained in a chitinous membrane which spreads out over the base of the sponge. The foraminal tubules are short and straight.
This sponge is allied toS. bombayensis, from which it is distinguished not only by the abnormal characters of its gemmule-spicules and the absence of flesh-spicules, but also by the form of its skeleton-spicules and the structure of its skeleton. I have examined several specimens dry and in spirit; butS. ultimais the only Indian freshwater sponge, exceptCorvospongilla burmanica, I have not seen in a fresh condition.
Typesin the Indian Museum; co-types at Trivandrum.
Habitat.Discovered by Mr. R. Shunkara Narayana Pillay, of the Trivandrum Museum, in a tank near Cape Comorin, the southernmost point of the Indian Peninsula.
Genus 2.PECTISPONGILLA,Annandale.
Pectispongilla, Annandale, Rec. Ind. Mus. iii, p. 103 (1909).
Type,Pectispongilla aurea, Annandale.
The structure of the sponge resembling that ofEuspongillaorEphydatia; but the gemmule-spicules bear at either end, at one side only, a double vertical row of spines, so that they appear when viewed in profile like a couple of combs joined together by a smooth bar.
Illustration: Fig. 20.—Gemmule and spicules of Pectispongilla aurea (type specimen). a, Skeleton-spicules; b, gemmule-spicules; b', a single gemmule-spicule more highly magnified.Fig. 20.—Gemmule and spicules ofPectispongilla aurea(type specimen).a, Skeleton-spicules;b, gemmule-spicules;b', a single gemmule-spicule more highly magnified.
Fig. 20.—Gemmule and spicules ofPectispongilla aurea(type specimen).a, Skeleton-spicules;b, gemmule-spicules;b', a single gemmule-spicule more highly magnified.
Geographical Distribution.—The genus is monotypic and is only known from Travancore and Cochin in the south-west of the Indian Peninsula.
15.Pectispongilla aurea*,Annandale.
Pectispongilla aurea, Annandale,op. cit., p. 103, pl. xii, fig. 2.
Spongeforming minute, soft, cushion-like masses of a deep golden colour (dull yellow in spirit); the surface smooth, minutely hispid. One relatively large depressed osculum usually present in each sponge; pores inconspicuous; dermal membrane in close contact with the parenchyma.
Skeletonconsisting of slender and feebly coherent radiating fibres as a rule two or three spicules thick, with single spicules or ill-defined transverse fibres running horizontally. Towards theexternal surface transverse spicules are numerous, but they do not form any very regular structure.
Spicules.Skeleton-spicules smooth, sharply pointed, straight or nearly so. Gemmule-spicules minute, with the stem smooth and cylindrical, relatively stout and much longer than the comb at either end; the two combs equal, with a number of minute, irregularly scattered spines between the two outer rows of stouter ones. No free microscleres.
Gemmulesminute, spherical, with a single aperture, which is provided with a very short foraminal tubule; the granular coat well developed; the spicules arranged in a slanting position, but more nearly vertically than horizontally, with the combs pointing in all directions; no external chitinous membrane.
The gemmule-spicules first appear as minute, smooth, needle-like bodies, which later become roughened on one side at either end and so finally assume the mature form. There are no bubble-cells in the parenchyma.
15a.Var.subspinosa*, nov.
This variety differs from the typical form in having its skeleton spicules covered with minute irregular spines or conical projections.
Typesof both the typical form and the variety in the Indian Museum; co-types of the typical form in the Trivandrum Museum.
Geographical Distribution.—The same as that of the genus.Localities:—Tenmalai, at the base of the western slopes of the W. Ghats in Travancore (typical form) (Annandale); Ernakulam and Trichur in Cochin (var.subspinosa) (G. Mathai).
Biology.—My specimens, which were taken in November, were growing on the roots of trees at the edge of an artificial pool by the roadside. They were in rather dense shade, but their brilliant golden colour made them conspicuous objects in spite of their small size. Mr. Mathai's specimens from Cochin were attached to water-weeds and to the husk of a cocoanut that had fallen or been thrown into the water.
Genus 3.EPHYDATIA,Lamouroux.
Ephydatia, Lamouroux, Hist. des Polyp. corall. flex.* p. 6 (fideWeltner) (1816).Ephydatia, J. E. Gray, P. Zool. Soc. London. 1867, p. 550.Trachyspongilla, Dybowsky (partim), Zool. Anz. i, p. 53 (1874).Meyenia, Carter (partim), Ann. Nat. Hist. (5) vii, p. 90 (1881).Carterella, Potts & Mills (partim), P. Ac. Philad. 1881, p. 150.Ephydatia, Vejdovsky, Abh. Böhm. Ges. xii, p. 23 (1883).Meyenia, Potts (partim),ibid.1887, p. 210.Carterella,id.(partim),ibid.1887, p. 260.Ephydatia, Weltner (partim), Arch. Naturg. lxi (i), p. 121 (1895).Ephydatia, Annandale, P. U.S. Mus. xxxvii, p. 404 (1909).
Type, (?)Spongilla fluviatilis, auctorum.
This genus is separated fromSpongillaby the structure of the gemmule-spicules, which bear at either end a transverse disk with serrated or deeply notched edges, or at any rate with edges that are distinctly undulated. The disks are equal and similar. True flesh-spicules are usually absent, but more or less perfect birotulates exactly similar to those associated with the gemmules are often found free in the parenchyma. The skeleton is never very stout and the skeleton-spicules are usually slender.
As has been already stated, some authors considerEphydatiaas the type-genus of a subfamily distinguished from the subfamily of whichSpongillais the type-genus by having rotulate gemmule-spicules. The transition between the two genera, however, is a very easy one. Many species of the subgenusEuspongilla, the typical subgenus ofSpongilla(includingS. lacustris, the type-species of the genus), have the spines at the ends of the gemmule-spicules arranged in such a way as to suggest rudimentary rotules, while in the typical form ofS. crateriformisthis formation is so distinct that the species has hitherto been placed in the genusEphydatia(Meyenia), although in some sponges that agree otherwise with the typical form of the species the gemmule-spicules are certainly not rotulate and in none do these spicules bear definite disks.
Geographical Distribution.—Ephydatia, exceptSpongilla, is the most generally distributed genus of the Spongillidæ, but in most countries it is not prolific in species. In Japan, however, it appears to predominate overSpongilla. Only one species is known from India, but another (E. blembingia*, Evans) has been described from the Malay Peninsula, while Weber found both the Indian species and a third (E. bogorensis*) in the Malay Archipelago.
16.Ephydatia meyeni* (Carter).
Spongilla meyeni, Carter, J. Bomb. Asiat. Soc. iii, p. 33, pl. i, fig. 1, & Ann. Nat. Hist. (2) iv, p. 84, pl. iii, fig. 1 (1849).Spongilla meyeni, Bowerbank, P. Zool. Soc. London, 1863, p. 448, pl. xxxviii, fig. 4.Spongilla meyeni, Carter, Ann. Nat. Hist. (5) vii, p. 93 (1881).Ephydatia fluviatilis, Weber, Zool. Ergeb. Niederländ. Ost-Ind. i. pp. 32, 46 (1890).Ephydatia mülleri, Weltner (partim), Arch. Naturg. lxi (i), p. 125 (1895).Ephydatia robusta, Annandale, J. Asiat. Soc. Bengal, 1907, p. 24, fig. 7.Ephydatia müllerisubsp.meyeni,id., Rec. Ind. Mus. ii, p. 306 (1908).
Spongehard and firm but easily torn, usually of a clear white, sometimes tinged with green, forming irregular sheets or masses never of great thickness, without branches but often with stout subquadrate projections, the summits of which are marked with radiating grooves; the whole surface often irregularly nodulose and deeply pitted; the oscula inconspicuous; the membrane adhering closely to the parenchyma.The parenchyma contains numerous bubble-cells(see p. 31, fig. 2).
Skeletondense but by no means regular; the radiating fibres distinct and containing a considerable amount of spongin, at any rate in the outer part of the sponge; transverse fibres hardly distinguishable, single spicules and irregular bundles of spicules taking their place.
Illustration: Fig. 21.—Gemmule and spicules of Ephydatia meyeni (from Calcutta). a, Skeleton-spicules; b, gemmule-spicules.Fig. 21.—Gemmule and spicules ofEphydatia meyeni(from Calcutta).a, Skeleton-spicules;b, gemmule-spicules.
Fig. 21.—Gemmule and spicules ofEphydatia meyeni(from Calcutta).a, Skeleton-spicules;b, gemmule-spicules.
Spicules.Skeleton-spicules entirely smooth, moderately stout, feebly curved, sharply pointed. No flesh-spicules. Gemmule-spicules with the shaft as a rule moderately stout, much longer than the diameter of one disk, smooth or with a few stout, straight horizontal spines, which are frequently bifid or trifid; the disks flat, of considerable size, with their margins cleanly and deeply divided into a comparatively small number of deep, slender, triangular processes of different sizes; the shaft extending not at all or very little beyond the disks.
Gemmulesspherical, usually numerous and of rather large size; each covered by a thick layer of minute air-spaces, among which the gemmule-spicules are arranged vertically, often in two or eventhree concentric series; a single short foraminal tubule; the pneumatic coat confined externally by a delicate membrane, with small funnel-shaped pits over the spicules of the outer series.
I think that the gemmules found by me in Bhim Tal and assigned to Potts'sMeyenia robustabelong to this species, but some of the spicules are barely as long as the diameter of the disks. In any case Potts's description is so short that the status of his species is doubtful. His specimens were from N. America.
E. meyeniis closely related to the two commonest Holarctic species of the genus,E. fluviatilisandE. mülleri, which have been confused by several authors including Potts. FromE. fluviatilisit is distinguished by the possession of bubble-cells in the parenchyma, and fromE. mülleriby its invariably smooth skeleton-spicules and the relatively long shafts of its gemmule-spicules. The latter character is a marked feature of the specimens from the Malay Archipelago assigned by Prof. Max Weber toE. fluviatilis; I am indebted to his kindness for an opportunity of examining some of them.
Typein the British Museum; a fragment in the Indian Museum.
Geographical Distribution.—India and Sumatra.Localities:—Bengal, Calcutta and neighbourhood (Annandale);Madras Presidency, Cape Comorin, Travancore (Trivandrum Mus.):Bombay Presidency, Island of Bombay (Carter):Himalayas, Bhim Tal, Kumaon (alt. 4,500 feet) (Annandale).
Biology.—My experience agrees with Carter's, that this species is never found on floating objects but always on stones or brickwork. It grows in the Calcutta "tanks" on artificial stonework at the edge of the water, together withSpongilla carteri,S. alba,S. fragilissubsp.calcuttana, andTrochospongilla latouchiana. It flourishes during the cold weather and often occupies the same position in succeeding years. In this event the sponge usually consists of a dead base, which is of a dark brownish colour and contains no cells, and a living upper layer of a whitish colour.
The larva ofSisyra indicais sometimes found in the canals, but the close texture of the sponge does not encourage the visits of otherincolæ.
Genus 4.DOSILIA,Gray.
Dosilia, J. E. Gray, P. Zool. Soc. London, 1867, p. 550.
Type,Spongilla plumosa, Carter.
This genus is distinguished fromEphydatiaby the nature of the free microscleres, the microscleres of the gemmule beingsimilarin the two genera. The free microscleres consist as a rule of several or many shafts meeting together in several or many planes at a common centre, which is usually nodular. The free ends of these shafts often possess rudimentary rotulæ. Occasionally a free microsclere may be found that is a true monaxon and sometimes such spicules are more or less distinctlybirotulate. The skeleton is also characteristic. It consists mainly of radiating fibres which bifurcate frequently in such a way that a bush-like structure is produced. Transverse fibres are very feebly developed and are invisible to the naked eye. Owing to the structure of the skeleton the sponge has a feathery appearance.
Gray originally applied the nameDosiliato this species and to"Spongilla" baileyi, Bowerbank. It is doubtful how far his generic description applies to the latter, which I have not seen; but although the position of"Spongilla" baileyineed not be discussed here, I may say that I do not regard it as a congener ofDosilia plumosa, the free microscleres of which are of a nature rare but not unique in the family. WithDosilia plumosawe must, in any case, associate in one genus the two forms that have been described as varieties, viz.,palmeri*, Potts from Texas and Mexico, andbrouini*, Kirkpatrick from the White Nile. By the kindness of the authorities of the Smithsonian Institution and the British Museum I have been able to examine specimens of all three forms, in each case identified by the author of the name, and I am inclined to regard them as three very closely allied but distinct species. Species with free microscleres similar to those of these three forms but with heterogeneous or tubelliform gemmule-spicules will probably need the creation of a new genus or new genera for their reception.
Geographical Distribution.—The typical species occurs in Bombay and Madras;D. palmerihas probably an extensive range in the drier parts of Mexico and the neighbouring States, whileD. brouinihas only been found on the banks of the White Nile above Khartoum, in Tropical Africa.
17.Dosilia plumosa* (Carter).