_Statoblasts._ Both fixed and free statoblasts are produced, but not in very large numbers. The latter are broadly oval and are surrounded by a stout chitinous ring, which often possesses irregular membranous projections; the surface is smooth. The free statoblasts are small and moderately elongate, the maximum breadth as a rule measuring about 2/3 of the length; the capsule is relatively large and the ring of air-cells is not very much broader at the ends than at the sides; the dorsal surface of the central capsule is profusely tuberculate. The outline of the whole structure is often somewhat irregular. In deference to Mr. Rousselet's opinion expressed in a letter I have hitherto regarded the Bombay form of this species as distinct from the African one, and there certainly is a great difference in the appearance of specimens taken on the lower surface of stones in Igatpuri Lake and of the types of _P. tanganyikæ_, one of which is now in the collection of the Indian Museum. The dark colour of the former, however, and their vigorous growth appear to be directly due to environment, for these characters disappear to a large extent in specimens growing on the stems of water-plants in the same lake. Indeed, such specimens are exactly intermediate between the form "_bombayensis_" and the typical form of the species. _P. tanganyikæ_ is closely allied to _P. philippinensis_, Kraepelin, from the island of Luzon, but the latter has a smooth and polished ectocyst devoid of annulations, and zooecia of a more elongate and regular form. TYPES of the species in the British and Indian Museums, those of _P. bombayensis_ in the latter collection. GEOGRAPHICAL DISTRIBUTION.--_P. tanganyikæ_ is only known as yet from L. Tanganyika in Central Africa and from Igatpuri in the Bombay Presidency. BIOLOGY.--In both localities the zoaria were found in shallow water. In L. Tanganyika they were encrusting stones and shells, while at Igatpuri they were fixed for the most part to the lower surface of stones but were also found on the stems of water-plants. My specimens from the Bombay Presidency were taken, on two separate occasions, at the end of November. At that date the zoaria were already decaying and large blanks, marked out by fixed statoblasts, were often observed on the stones. Probably, therefore, the species flourishes during the "rains." 35. Plumatella punctata, _Hancock_. (Plate IV, fig. 5.) _Plumatella punctata_, Hancock, Ann. Nat. Hist. (2) v, p. 200, pl. iii, fig. 1, and pl. v, figs. 6, 7 (1850). _Plumatella vesicularis_, Leidy, P. Ac. Philad. vii, p. 192 (1854). _Plumatella vitrea_, Hyatt, Comm. Essex Inst. iv, pl. ix, figs. 1, 2 (1866). _Plumatella punctata_, Allman, Mon. Fresh-Water Polyzoa, p. 100, fig. 15 (1857). _Plumatella vesicularis_, _id._, _ibid._ p. 101. _Plumatella vitrea_, Hyatt, Proc. Essex Inst. v, p. 225, figs. 18, 19 (1868). _Plumatella vesicularis_, _id._, _ibid._ p. 225.