Length of skeleton-spicule 0.2859 mm. Greatest diameter of skeleton-spicule 0.014 " Length of gemmule-spicule 0.032-0.036 mm. Length of comb of gemmule-spicule 0.008 mm. Greatest diameter of shaft of gemmule-spicule 0.004 " Diameter of gemmule 0.204-0.221 mm. The gemmule-spicules first appear as minute, smooth, needle-like bodies, which later become roughened on one side at either end and so finally assume the mature form. There are no bubble-cells in the parenchyma. 15_a._ Var. subspinosa*, nov. This variety differs from the typical form in having its skeleton spicules covered with minute irregular spines or conical projections. TYPES of both the typical form and the variety in the Indian Museum; co-types of the typical form in the Trivandrum Museum. GEOGRAPHICAL DISTRIBUTION.--The same as that of the genus. _Localities_:--Tenmalai, at the base of the western slopes of the W. Ghats in Travancore (typical form) (_Annandale_); Ernakulam and Trichur in Cochin (var. _subspinosa_) (_G. Mathai_). BIOLOGY.--My specimens, which were taken in November, were growing on the roots of trees at the edge of an artificial pool by the roadside. They were in rather dense shade, but their brilliant golden colour made them conspicuous objects in spite of their small size. Mr. Mathai's specimens from Cochin were attached to water-weeds and to the husk of a cocoanut that had fallen or been thrown into the water. Genus 3. EPHYDATIA, _Lamouroux_. _Ephydatia_, Lamouroux, Hist. des Polyp. corall. flex.* p. 6 (_fide_ Weltner) (1816). _Ephydatia_, J. E. Gray, P. Zool. Soc. London. 1867, p. 550. _Trachyspongilla_, Dybowsky (_partim_), Zool. Anz. i, p. 53 (1874). _Meyenia_, Carter (_partim_), Ann. Nat. Hist. (5) vii, p. 90 (1881). _Carterella_, Potts & Mills (_partim_), P. Ac. Philad. 1881, p. 150. _Ephydatia_, Vejdovsky, Abh. Böhm. Ges. xii, p. 23 (1883). _Meyenia_, Potts (_partim_), _ibid._ 1887, p. 210. _Carterella_, _id._ (_partim_), _ibid._ 1887, p. 260. _Ephydatia_, Weltner (_partim_), Arch. Naturg. lxi (i), p. 121 (1895). _Ephydatia_, Annandale, P. U.S. Mus. xxxvii, p. 404 (1909). TYPE, (?) _Spongilla fluviatilis_, auctorum. This genus is separated from _Spongilla_ by the structure of the gemmule-spicules, which bear at either end a transverse disk with serrated or deeply notched edges, or at any rate with edges that are distinctly undulated. The disks are equal and similar. True flesh-spicules are usually absent, but more or less perfect birotulates exactly similar to those associated with the gemmules are often found free in the parenchyma. The skeleton is never very stout and the skeleton-spicules are usually slender.