172 Mr. A. H. Hassall’s Catalogue of Irish Zoophytes. 
about an inch and a half in height ; each tuft is composed of nume- 
rous separate polypidoms, closely interwoven with each other, and 
dichotomously branched. The.cells are of an oblong square form, 
slightly enlarged distally, and furnished with a globular operculum 
somewhat similar to that of F. avicularis. 
F. avicularis. This species has four spines at the top of each cell. 
Parasitic on other corallines; rare ; Dublin bay. 
F, membranacea. On the frond of Laminaria digitata; very 
abundant ; common. 
F. Hibernica. Polypidom encrusting calcareous, white; cells 
hexagonal, excavated, dotted on the inside.—A. H. 
The only specimens I have obtained of this are parasitic on an 
Ascidia ; I have little doubt, however, of its being a new species. 
The Flustra to which it bears the closest resemblance is perhaps 
F. carbasea, but I have never met with it on this part of the Irish 
coast. See Plate VII. fig. 1. 
CELLULARIA. 
Cellularia ciliata.—Dublin bay ; rare. 
C. scruposa. On the roots of most corallines and old shells; 
abundant ; Dublin and Killiney bays. 
C. reptans. Everywhere very common. 
C. Avicularia. This species is, I think, misplaced ; it ought ra- 
ther to be associated with Flustra than Cellularia. 
Dublin bay; rare. 
ACAMARCHIS. 
Acamarchis plumosa.—Dublin bay ; rare. 
FARCIMIA. 
Farcimia salicornia. ‘‘ Articulations cylindrical; cells rhomboidal, 
plain.” 
Farcimia sinuosa. Cells rounded above, excavated below for the 
reception of the head of the succeeding cell; aperture semicircular, 
situated in the upper third of each cell.—A. H. 
I have but little hesitation in pronouncing this to be a new spe- 
cies*. It differs from the ordinary species in the greater size of the 
cylinders, in the shape of the cells (too material to be the result of 
any accidental circumstances), and above all, in the position of the 
aperture, which in this is placed in the upper part of each cell, while 
in F. salicornia it is exactly central. This last I consider to be the 
most important distinction of all. The number of the cells on each 
cylinder is also much greater than in the preceding species. See 
Plate VI. fig. 1. 2. 
* Among several specimens of salicornia, collected by Mrs. Alder and 
Miss Amelia Hunter, at Blackrock, Dublin bay, I observed some of Farci- 
mia sinuosa, agreeing in every particular with my own previously obtained 
at Menion, about two miles from the former place. The authority for this 
new species does not now, therefore, rest upon the examination of a single 
specimen. 
