_Biology._ The external form of the sponge is due in great part to its environment. Specimens on small stones from the bottom of the Kumaon Lakes consist of thin disk-like films, often not more than a few centimetres in diameter and a few millimetres thick: others, growing on thin twigs, are elevated and compressed, resembling a cockscomb in appearance, while others again form nodules and masses of irregular form among the branches of delicate water-weeds. Some of these last are penetrated by zoaria of _Fredericella indica_. Weltner has published some very interesting observations on the seasonal variation of minute structure in European representatives of the species (Arch. Naturg. Berlin, lxxiii (i), p. 273 1907) and has discussed the formation of the abnormal spicules that sometimes occur (_ibid._ lxvii (Special Number), p. 191, pls. vi, vii, figs. 27-59, 1901). Genus CORVOSPONGILLA (p. 122). After _Corvospongilla burmanica_, p. 123, add a new species:-- Corvospongilla caunteri, nov. _Sponge_ forming thin films of considerable area not more than 3 or 4 mm. thick, of a bright green colour, moderately hard but friable. The surface smooth; oscula inconspicuous, surrounded by shallow and ill-defined radiating furrows; a very stout basal membrane present. [Illustration: Fig. 48.--_Corvospongilla caunteri_ (type, from Lucknow). A=Gemmule; B=gemmule-spicules; C=flesh-spicules; D=Skeleton-spicules.] _Skeleton_ reticulate but almost devoid of spongin, the reticulations close but formed mainly by single spicules; skeleton-fibres barely distinguishable. A close layer of spicules lying parallel to the basal membrane. _Spicules._ Skeleton-spicules variable in size and shape, almost straight, as a rule smooth, moderately stout, blunt or abruptly pointed; sometimes roughened or spiny at the tips, often sharply pointed. Flesh-spicules minute, few in number, with smooth, slender shafts which are variable in length, never very strongly curved; the terminal spines relatively short, not strongly recurved. Gemmule-spicules amphistrongylous or amphioxous, irregularly spiny, slender, of variable length. _Gemmules_ free in the substance of the sponge, spherical or somewhat depressed, very variable in size but never large, having a thick external pneumatic coat in which the air-spaces are extremely small and, inside this coat, a single rather sparse layer of spicules lying parallel to the gemmule. A single depressed aperture present. TYPE in the Indian Museum. HABITAT. Hazratganj, Lucknow; on piers of bridge in running water (_J. Caunter_, 29-30. iv. 11).