_Hyalinella vesicularis_, Jullien, Bull. Soc. zool. France, x, p. 133, figs. 165-172 (1885). _Hyalinella vitrea_, _id._, _ibid._ p. 134, figs. 173-179. _Plumatella punctata_, Kraepelin, Deutsch. Süsswasserbryozoen, i, p. 126, pl. iv, figs. 115, 116; pl. v, figs. 124, 125; pl. vii, figs. 153, 154 (1887). _Plumatella vesicularis_, Braem, Unters. ü. Bryozoen süssen Wassers, p. 8, pl. i, fig. 8 (Bibl. Zool. ii) (1890). _Hyalinella punctata_, Loppens, Ann. Biol. lacustre, iii, p. 163 (1908). _Plumatella punctata_, Annandale, Rec. Ind. Mus. v, p. 52 (1910). _Zoarium._ The zoarium is entirely recumbent and often appears to form an almost uniform flat layer instead of a dendritic body. Sometimes, however, it is distinctly linear, with lateral branches produced irregularly at considerable distances apart. _Zooecia._ The zooecia differ from those of all other species in having a greatly swollen, soft ectocyst which can be transversely wrinkled all over the zooecium by the action of the muscles of the polypide and is distinctly contractile. It is mainly owing to the swollen and almost gelatinous nature of the ectocyst that the dendritic character of the zoarium is frequently concealed, for the method of branching is essentially the same as that of _P. diffusa_, although the zooecia are not so distinctly elbowed. The ectocyst is colourless or faintly tinted with brown; as a rule it is not quite hyaline and the external surface is minutely roughened or tuberculate. The zooecia are not emarginate or furrowed. _Statoblasts._ Stationary statoblasts are not found. The free statoblasts are variable and often asymmetrical in outline, but the free portion of the swim-ring is always of nearly equal diameter all round the periphery and the capsule relatively large. Some of the statoblasts are always broad in comparison with their length. _Polypide._ The polypide is comparatively short and stout. European specimens are said to have from 30 to 40 tentacles, but Indian specimens have only from 20 to 30.