_Norodonia sinensis_, _id._, _ibid._ p. 78, figs. 1-3. _Norodonia cambodgiensis_, _id._, _ibid._ x, p. 181, figs. 244, 245 (1885). _Norodonia sinensis_, _id._, _ibid._ p. 182, figs. 246, 247. _Hislopia lacustris_, Annandale, J. As. Soc. Bengal (new series) iii, p. 85 (1907). _Hislopia lacustris_, Walton, Rec. Ind. Mus. i, p. 177 (1907). _Hislopia lacustris_, Kirkpatrick, _ibid._ ii, p. 98 (1908). _Hislopia lacustris_, Walton, _ibid._ iii, p. 295 (1909). _Zoarium._ The zoarium forms a flat, more or less solid layer and is closely adherent to foreign objects. As a rule it covers a considerable area, with radiating branches at the edges; but when growing on slender twigs or the stems of water-plants it forms narrow, closely compressed masses. One zooecium, however, never grows over another. _Zooecia._ The zooecia are variable in shape. In zoaria which have space for free expansion they are as a rule irregularly oval, the posterior extremity being often narrower than the anterior; but small triangular zooecia and others that are almost square may often be found. When growing on a support of limited area the zooecia are smaller and as a rule more elongate. The orifice is situated on a slight eminence nearer the anterior than the posterior margin of the dorsal surface. It is surrounded by a strong chitinous rim, which is usually square or subquadrate but not infrequently circular or subcircular. Sometimes a prominent spine is borne at each corner of the rim, but these spines are often vestigial or absent; they are rarely as long as the transverse diameter of the orifice. The zooecium is usually surrounded by a chitinous margin, and outside this margin there is often a greater or less extent of adherent membrane. In some zooecia the margin is obsolete or obsolescent. The dorsal surface is of a glassy transparency but by no means soft. [Illustration: Fig. 39.--_Hislopia lacustris._ A=part of a zoarium of the subspecies _moniliformis_ (type specimen, from Calcutta), × 15; A=green cysts in gizzard; E=eggs. B=outline of part of a zoarium of the typical form of the species from the United Provinces, showing variation in the form of the zooecia and of the orifice, × 15.] _Polypide._ The polypide has from 12 to 20 tentacles, 16 being a common number. TYPE probably not in existence. It is not in the British Museum and Prof. Dendy, who has been kind enough to examine the specimens from Carter's collection now in his possession, tells me that there are none of _Hislopia_ among them. 27 _a._ Subsp. moniliformis, nov. _Hislopia lacustris_, Annandale, J. As. Soc. Bengal (new series) ii, p. 59, fig. 1 (1906).