BIOLOGY.--This subspecies is usually found in small masses of water, especially in pools of rain-water, but Mr. Mackenzie found it growing luxuriantly in the Jharai at a time of flood in September. It is very abundant in small pools among the sand-dunes that skirt the greater part of the east coast of India. Here it grows with great rapidity during the "rains," and often becomes desiccated even more rapidly as soon as the rain ceases. As early in the autumn as October I have seen masses of the sponge attached, perfectly dry, to grass growing in the sand near the Sur Lake in Orissa. They were, of course, dead but preserved a life-like appearance. Some of them measured about six inches in diameter. At Port Canning the sponge grows during the rains on the brickwork of bridges over ditches of brackish water that dry up at the beginning of winter, while at Rajshahi and at Igatpuri I found it at the edges of small ponds, at the latter place in November, at the former in February. Specimens taken at Madras by Dr. Henderson during the rains in small ponds in the sand contained no gemmules, but these structures are very numerous in sponges examined in autumn or winter. Numerous larvæ of _Sisyra indica_ (p. 92) were found in this sponge at Rajshahi. Unlike those obtained from _S. alba_, they had a green colour owing to the green matter sucked from the sponge in their stomachs. The _coralloides_ phase of _Plumatella fruticosa_ (p. 219) was also found in _S. lacustris_ subsp. _reticulata_ at Rajshahi. So far as my experience goes, this subspecies has always a bright green colour due to the presence of "green corpuscles," even when it is growing in a pond heavily shaded by trees or under the arch of a small bridge. Probably the more intense light of India enables the corpuscles to flourish in situations in which in Europe they would lose their chlorophyll. 2. Spongilla proliferens*, _Annandale_. _Spongilla cinerea_, Weber (_nec_ Carter), Zool. Ergeb. Niederl. Ost-Ind. vol. i, pp. 35, 46 (1890). _Spongilla proliferens_, Annandale, J. Asiat. Soc. Bengal, 1907, p. 15, fig. 1. _Spongilla proliferens_, _id._, Rec. Ind. Mus. i, pp. 267, 271 (1907). _Sponge_ forming soft, shallow cushions rarely more than 10 cm. in diameter on the leaves of water-plants, or small irregular masses on their roots and stems. Colour bright green. Oscula moderate, flat, surrounded by deep, cone-shaped collars; radiating furrows and canals in the parenchyma surrounding them often deep. External pores contained normally in single cells. The surface frequently covered by small rounded buds; true branches if present more or less flattened or conical, always short, as a rule absent. _Skeleton_ loose, feebly reticulate at the base of the sponge; transverse fibres slender in the upper part of the sponge, often scarcely recognizable at its base. Very little spongin present.