This sponge is allied to _S. 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; but _S. ultima_ is the only Indian freshwater sponge, except _Corvospongilla burmanica_, I have not seen in a fresh condition. TYPES in 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 of _Euspongilla_ or _Ephydatia_; 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.] 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. _Sponge_ forming 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. _Skeleton_ consisting 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 the external 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. _Gemmules_ minute, 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.