Acamarchis. 
Z. ASC1DI0IDA. 
293 
moved upwards and downwards with the regularity of a pendulum. 
The polypes have apparently twelve tentacula. 
The cells have the characters of Acamarchis or Flustra rather than 
of Cellularia. Many naturalists make the zoophyte a vari ety of Flustra 
avicularia, but Mr Bean and Milne Edwards dissent from this associa- 
tion. The principal distinction between them lies in the dissimi- 
larity of their habit : in the shape of the cells I do not perceive any 
noticeable difference, but in this I have never seen more than two 
spines at the top of each cell, while in the Flustra 1 have seen four 
on some cells, though certainly many of them are armed with two 
only. 
5. C. hookeri, “ cells rounded, diverging, projecting.” — Sir 
W. J. Hooker. 
Cellularia Hookeri, Flem. Brit. Anim. 539 La Bicellaire de Hooker, 
Blainv . Actinol- 460. 
Hab. “ Found by Dr Hooker at Torquay, 1812,” Fleming. 
“ H eighth upwards of an inch, dichotomously branched, branches 
straight, stiff, brittle, divaricate ; the cells are protuberant dorsally, 
and their rounded top is nearly free, projecting laterally, giving the 
edge a remarkably jagged outline, and the pearly ovaria are rounded.” 
Fleming. — This is probably syonymous with Cellarict denticulata 
of Lamarck, Anim. s. vert. ii. 137. 
37. Acamarchis,* Lamouroux. 
Character. Polypidom plant-like, subcalcareous, attached 
by fibrous radicles, bushy, dichotomously branched, the branches 
composed of a double series of semialternate oblong cells whose 
apertures occupy nearly one side and face one way, usually pro- 
tected by an operculum. — Polypes ascidian. 
1. A. neritina, 66 cells quadrangular, lengthened, with a 
truncated summit, the outer angle projecting — Miss Blackburne. 
Remarkable Coralline, Ellis in Phil. Trans, abridg. x. 345, pi. 8, fig. a, A. 
G . Ellis, Corall. 35, pi. 19 Sertularia neritina, Lin. Syst. 1315. 
Turt. Gmel. iv- 685. Stew. Elem. ii. 448 Cellularia neritina, 
Pall. Elench. 67. Flem. Brit. Anim. 539 Cellaria neritina, Ellis and 
Soland. Zooph. 22. Bose, Vers, iii. 131. Lam. Anim. s. vert ii. 
140. 2de edit, ii- 190 Acamarchis neritina, Corall. 58, pi. 3, fig. 2. 
Risso, l’Europ. Merid. v. 318. Blainv. Actinolog. 459, pi. 77, fig. 3. Tem- 
pleton in Mag. Nat. Hist. ix. 469. 
Hab. On the English coast, very rare. “ I possess a specimen 
* The name of one of the daughters of Oceanus, 
