Prof. Weber's specimens of _S. bombayensis_ were 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 of _Plumatella_ of which they occasionally contain a statoblast. 14. Spongilla ultima*, _Annandale_. (Plate II, fig. 3.) _Spongilla ultima_, Annandale, Rec. Ind. Mus. v, p. 31 (1910). _Sponge_ hard 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. _Skeleton_ forming 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.] _Gemmules_ adherent, 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.