GEOGRAPHICAL DISTRIBUTION.--The genus is widely distributed in the tropics of both Hemispheres, its headquarters apparently being in S. America; but it is nowhere rich in species. Only two are known from the Oriental Region, namely _T. vesparium_* from Borneo, and _T. vesparioides_* from Burma. 21. Tubella vesparioides*, _Annandale_. (Plate II, fig. 4.) _Tubella vesparioides_, Annandale, Rec. Ind. Mus. ii, p. 157 (1908). _Sponge_ forming rather thick sheets of considerable size, hard but brittle, almost black in colour; oscula inconspicuous; external membrane supported on a reticulate horizontal skeleton. _Skeleton._ The surface covered with a network of stout spicule-fibres, the interstices of which are more or less deeply sunk, with sharp fibres projecting vertically upwards at the nodes; the whole mass pervaded by a similar network, which is composed of a considerable number of spicules lying parallel to one another, overlapping at the ends and bound together by a profuse secretion of spongin. [Illustration: Fig. 25.--Spicules of _Tubella vesparioides_ (from type specimen). × 240.] _Spicules._ Skeleton-spicules slender, smooth, amphioxous, bent in a wide arc or, not infrequently, at an angle. No true flesh-spicules. Gemmule-spicules terminating above in a rounded, knob-like structure and below in a relatively broad, flat rotula, which is very deeply and irregularly indented round the edge when mature, the spicules at an earlier stage of development having the form of a sharp pin with a round head; shaft of adult spicules projecting slightly below the rotula, long, slender, generally armed with a few stout conical spines, which stand out at right angles to it. _Gemmules_ numerous throughout the sponge, spherical, provided with a short, straight foraminal tubule, surrounded by one row of spicules, which are embedded in a rather thin granular coat. Average length of skeleton-spicule 0.316 mm. " breadth of skeleton-spicule 0.0135 " " length of gemmule-spicule 0.046 " " diameter of rotula 0.0162 " " " gemmule 0.446 " This sponge is closely related to _Tubella vesparium_ (v. Martens) from Borneo, from which it may be distinguished by its smooth skeleton-spicules and the deeply indented disk of its gemmule-spicules. The skeleton-fibres are also rather less stout. By the kindness of Dr. Weltner, I have been able to compare types of the two species. TYPE in the Indian Museum. HABITAT.--Taken at the edge of the Kanghyi ("great pond") at Mudon near Moulmein in the Amherst district of Tenasserim. The specimens were obtained in March in a dry state and had grown on logs and branches which had evidently been submerged earlier in the year. The name _vesparium_ given to the allied species on account of its resemblance to a wasps' nest applies with almost equal force to this Burmese form. Genus 7. CORVOSPONGILLA, nov.