294 Z. ASCIDXOIDA. ^Acamarchis, 
from the collection of the late Dr Walker, which he received from 
Miss Blackburne from the coast of Cheshire,” Fleming. “ Found 
in Dublin Bay and Belfast Lough,” Templeton. 
“ Height several inches, dichotomously divided, spreading ; the 
cells are narrow, rather diverging, and more than the half of the outer 
summit is free ; the pearly helmet-shaped ovaria opening transversely, 
were at one time considered by Ellis as the young of Neritae.” Flem- 
ing. 
2. A. plumosa, cells linear-oblong , with a spine at the outer 
and upper angle ; the aperture elliptical , entire . Doody. 
Plate xxxix. 
Corallina pumila erecta ramosior, Raii, Syn. i. 37, no. 20, tab. 2, fig. 1. 
Ellis, in Phil. Trans, abridg. x. 346, pi. 8, fig. b, B-D Soft feather- 
ed coralline, Ellis , Corall. 33, no. 1, pi. 18, fig. a, A Sertularia 
fastigiata, Lin. Syst. 1314. Fabric. Faun. Grcenl. 445. Turt. Gmel. 
iv. 684. Berk. Syn. i. 219. Turt. Brit. Faun. 216. Wern. Mem. i. 
565. Stew. Elem. ii. 448 Cellularia plumosa, Pall. Elench. 66. 
Hogg's Stock. 35 C. fastigiata, Blumenb. Man. 273. Elem. Brit. 
Anim. 539 Cellaria plumosa, Ellis and Soland. Zooph. 21. Bose , 
Vers, iii. 131. Lam. Anim. s. Vert. ii. 140. 2de edit. ii. 190. Crisia 
plumosa, Corall. 62 C. fastigiata, Templeton in Mag. Nat. Hist. ix. 
468. La Bicellaire plumeuse, Blainv. Actinolog. 459. 
Hab. “ Not uncommon beyond low water-mark,” Fleming. Leith 
shore, Jameson . In deep water at Scarborough, common, Mr Bean. 
Rare in Berwick Bay, G. J. a Common on the coast” of Ireland, 
Templeton. 
Polypidom attached by fibrous roots, subcalcareous, caulescent, 
erect, from 2 to 4 inches high, very much branched, the branches 
panicled, dichotomous, with linear or filiform segments ; cells oblong 
with a short pointed spine on the superior outer angle, smooth, pel- 
lucid or somewhat crystalline, marked always with a black or orange - 
coloured dot near the centre, the remains of the dried polype ; ovaries 
pearly, globular or pear-shaped, placed over the apertures. 
In habit this fine species is sometimes like Sertularia argentea, but 
in general it is more tufted and bushy. Specimens occur without 
an ovary on any cell, while others are loaded with them ; and in one 
of the latter sort I found some of the segments of the branches com- 
posed of a triple series of cells. The whole polypidom is often co- 
loured of a pink or purplish hue. In an old condition the cells be- 
come obsolete, and the habit of the species so altered, as to render 
its detection in this guise somewhat difficult to the inexperienced. 
Dr Fleming does not adopt this genus, which Blainville is also of 
