32 



TUNICATA. 



posed of thorax, fore-abdomen, and hind-abdomen ; 

 branching orifice six-rayed; anal orifice simple, 

 indistinct. 



A. ficus. 

 fallax. 



Fig. 43 ; n. s. and ', 



A. nutans. 

 verrucosum. 



Sidnyum (Sav.). Mass a number of cones 

 truncated and starred at the summit, rising from a 

 common encrusting base, each including one sys- 

 tem with a depressed centre. Animals composed 

 of thorax and abdomen; branchial orifice eight- 

 rayed. 



S. turbinatum. Fig. 44 ; n. s. 



43 



n 



Polyclinum (Sav.). Mass sessile, varying 

 form, gelatinous or cartilaginous, composed of nu- 

 merous systems, which are convex and radiating, 

 with a central cavity. Animals composed of 

 thorax, fore-abdomen, and a long-stalked hind- 

 abdomen ; branchial orifice six-rayed ; anal orifice 

 projecting horizontally. 



P. aurantium. Fig. 45 ; n. s. 



