1*28 
BiRD’S-HEAD CORALLINE. C. Avicularia. Calca- 
reous, erect, dichotomously branched ; cells glandular, 
opening on one plane, with an erect spine at each superior 
angle, and the rudiments of two others below, crossing tb® 
diameter. 
Bird’s-head Coralline, Ellis’s Coral., p. 36, pi. 20, fig- a 
A. Serlnlaria avicularia, Turton’s Lin., vol. 4, p. 685* 
Stewart’s Elem., vol. 2, p. 448. Cellaria avicularia, Ell* 9 
and Solander’s Zooph., p. 22. Crisia avicularia, LanioU' 
rous’s Cor. Flex., p. 141. Templeton in Mag. Nat. His 1 -' 
vol. !), p. 468. Cellnlaria avicularia, Johnston’s Brit. Zooph-> 
p. 292, pi. 36, fig. 78. 
Hub. On the back of the Corwich crab ; at low water 
mark. Mevagissey bay. Mount’s bay. 
This beautiful and delicate coralline is by no means cofli' 
mon ; compared with the others of this genus, it is more 
bushy, erect, and graceful. It is calcareous, erect, dicbO' 
tomously branched, and varies in height from one 
to one and three quarters. When living it is very elast'® 
and of a delicate fiesh colour ; but when dead, it is white a 11 
brittle. It is rooted by matted tubular fibres, and it arises bj 
a small round stem, which soon begins to divide and branch* 
The branches are formed of two rows of alternating c®* 
which open on one plane. The cells are quadrangm 8 
and have a spine at each superior angle which point up' 
wards; below these are two others, one on each side, win® 
cross the diameter of the cell; these last are sometio' 6 
abseut or in so rudimentary a state as scarcely to be note j 
The apertures, like those of Flustra, are subterminal 8 ® 
transverse, and are covered with pearly shield-like opercul 8 ’ 
which become elevated between the superior spines in dy ,n j 7 ' 
On the external edges of the cells, there are frequen 1 
appendages, resembling birds heads, to be seen, which 
to and from with the regularity of a pendulum, at the s* 1 ' 
time they open and shut their bills like a bird. This spec 1 
has been considered the young state of Flustra avicularia l 
some authors, but from this I dissent, and the reasons 
which are briefly noticed under Flustra avicularis. 
CELLULARIA PLUMOSA. Confervoid ; cells bin*' 8 ’ 
alternate, opening on one plane; apertures irregu' 8 
elliptical, with a stout spine on the outer and upper niurb 
ei O' 
PI. xxiii., fig. 4. 
ol, 
h 
Corallina pumila erecta ramosior, Raii, Synop., 
p. 37, pi, 2, fig.l. Soft Feathered Coralline, Ellis 
p. 33, pi. 18, fig. a A. Sertularia fastigiata, Turton s 
Vol. 4, p. 684. Stewart's Elem., vol. 2, p. 448. Cellu 
LiU" 
