? 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).
Fig. 15.—Spongilla fragilis subsp. 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 at the 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.
Type in the Indian Museum.
9 b. 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's Spongilla decipiens in 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 subspecies calcuttana, most of the skeleton-spicules of which are much less sharp than those of decipiens. 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.