_Polypide._ There are about 40 tentacles, the velum at the base of which extends upwards for a considerable distance without being festooned. The stomach is elongate and slender and narrowly rounded at the base. The method of branching, the coloration of the zooecia and the form of the free statoblast are all characteristic. Luxuriant or closely compressed zoaria of _P. diffusa_ often bear a superficial resemblance to those of _P. emarginata_, but the resemblance disappears if they are carefully dissected out. Indian specimens of _P. emarginata_ agree closely with European ones. GEOGRAPHICAL DISTRIBUTION.--_P. emarginata_ is a common species in Europe, N. America, and southern Asia and probably also occurs in Africa and Australia. I have examined specimens from Calcutta, Rangoon, and Mandalay in Indian territory, and also from Jalor in the Patani States (Malay Peninsula) and the Talé Noi, Lakon Sitamarat, Lower Siam. Gemmules found by Apstein (Zool. Jahrb. (Syst.) xxv, 1907, p. 201) in plankton from the Colombo lake may belong to this species or to any of the others included by Kraepelin in his _P. princeps_. BIOLOGY.--In Ireland Allan found _P. emarginata_ in streams and rivulets, but it also occurs in European lakes. In India I have only found it in ponds. It prefers to adhere to the surface of stones or bricks, but when these are not available is found on the stems of water-plants. In the latter position the form called _Alcyonella benedeni_ by Allman is usually produced, owing to the fact that the upright branches are crowded together through lack of space, very much in the same way (although owing to a different cause) as those of _P. fruticosa_ are crowded together in the _coralloides_ phase, to which the _benedeni_ phase of _P. emarginata_ is in many respects analogous. Although it is essentially a cold-weather species in Calcutta, _P. emarginata_ is sometimes found in a living condition during the "rains." Zoaria examined at this season, however, contains few living polypides, the majority of the zooecia having rotted away and left fixed statoblasts only to mark their former position. 31. Plumatella javanica, _Kraepelin_. _Plumatella javanica_, Kraepelin, Mitt. Nat. Mus. Hamb. xxiii, p. 143, figs. 1-3 (1903). _Plumatella emarginata_ var. _javanica_, Loppens, Ann. Biol. lacustre, iii, p. 162 (1908). _Plumatella javanica_, Annandale, Rec. Ind. Mus. v, p. 50 (1910). _Plumatella allmani_ var. _dumortieri_, _id._ (_partim_) (_nec_ Allman), _ibid._ p. 49. This species is related to _P. emarginata_, from which it may be distinguished by the following characters:-- _Zoarium._ The zoarium is always entirely recumbent and branches sparingly; its method of branching does not approach the dichotomous type but is lateral and irregular. Linear series of zooecia without lateral branches are often formed.