The form Allman called _P. coralloides_ was found by him, "attached to floating logs of wood, together with _P. repens_ and _Cordylophora lacustris_, and generally immersed in masses of _Spongilla fluviatilis_." I have always found it immersed in sponges (_S. lacustris_, _S. alba_, _S. carteri_, and _S. crassissima_), except when the sponge in which it had been immersed had decayed. Indeed, the peculiar form it has assumed appears to be directly due to the pressure of the growing sponge exerted on the zooecia, for it is often possible to find a zoarium that has been partially overgrown by a sponge and has retained its typical form so long as it was free but has assumed the _coralloides_ form where immersed.[BI] In Shasthancottah Lake, Travancore, I found specimens of the _stricta_ phase embedded in the gelatinous mass formed by a social rotifer and to some extent assimilated to the _coralloides_ form.
[Footnote BI: Braem (_op. cit._, p. 3, pl. i, fig. 1), has described and figured under the name _P. fungosa_ var. _coralloides_, Allman, a dense form that somewhat resembles this phase of _P. fruticosa_ but has become compacted without external pressure. It is, however, probably a form of _P. repens_ rather than _P. fungosa_ and differs in its broad statoblasts from any form of _P. fruticosa_. I have examined specimens of the same form from England.]
30. Plumatella emarginata, _Allman_. (Plate III, fig. 2; plate IV, figs. 1, 1 _a._)
_Plumatella emarginata_, Allman, Ann. Nat. Hist. xiii, p. 330 (1844).
_Plumatella emarginata_, Johnston, Brit. Zooph. (ed. 2), p. 404 (1847).
_Alcyonella benedeni_, Allman, Mon. Fresh-Water Polyzoa, p. 89, pl. iv, figs. 5-11 (1857).
_Plumatella emarginata_, _id._, _ibid._ p. 104, pl. vii, figs. 5-10.
_Plumatella lucifuga_, Jullien, Bull. Soc. zool. France, x, figs. 89, 90, p. 114 (1885).
_Plumatella princeps_ var. _emarginata_, Kraepelin (_partim_), Deutsch. Süsswasserbryoz. p. 120, pl. iv, fig. 108, pl. v, fig. 123 (1887).
_Plumatella emarginata_, Braem, Unter. ii. Bryoz. süssen Wassers, p. 9, pl. i, figs. 12, 14 (Bibl. Zool. ii) (1890).
_Plumatella emarginata_, Annandale (_partim_), J. As. Soc. Bengal, (new series) iii, 1907, p. 89.
_Plumatella princeps_, Loppens (_partim_), Ann. Biol. lacustre, iii, p. 162, fig. 7 (1908).