POLYZOA. 67 
the cell, they are protected above by a membranous comb-like 
frill. 
The cells either bud off from each other or arise as buds on a 
stolon or stem. 
Alcyonidium gelatinosum* (Fig. 17), so called from its resemblance Case A, 
to the zoophyte Alcyonium, forms fleshy translucent growths JJPJ.J g 
occurring in the form of nodulated branched masses, or of long 
Fisr. 17. 
part. 
Alcyonidium gelatinosum. A, a small piece, natural size ; B, the 
same magnified. 
finger-like growths. The species is common round our coasts 
where it grows attached to stones and shells near low-water 
mark. 
Amathia forms bushy growths composed of slender horny branches. 
The cells, which are cylindrical or squarish, rise from the branches 
in biserial rows like Pan's pipes. In Amathia lendigera * (Fig. 18) the Case A, 
groups of cells are well separated from each other, but in A. spiralis* upright 
and A. convoluta* the cells form a nearly or entirely continuous series pa ' 
winding in a spiral round the slender stems. In Boweroankia 
imbricata* the cells are clustered on the stems. Vesicularia spinosa*, 
F 2 
