MoUuscoida (including 



OF THE MOLLUSCOIDA AND CCELENTERATA. 521 



&c., amongst the Tunicata. In accordance with these views the following classi- 

 fication may be given : — 



( With primary hsemal \ . . ,. 



Intestine insulated from j and final neural flexure, j 



^ „ ^ ^ the somatic cavity, . ^ With simple neural) Brachiopoda 



the Ctenophora)] ■ • " 1 ' flexure, ..... j and Polyzoa. 



Intestine straight, and communicating with the 1 „ , 



(^somatic cavity, j " 



( Intestine obliterated ; stomach communicating with ) . , • 

 - ,. I ,, ,■ -J. >■ Actmozoa. 



Ccelenterata (excludmg J the somatic cavity, j 



the Ctenophora), . . i True stomach obliterated, its ofl&ce being answered \ „ , 



' by the somatic cavity, 3 



* These are probably in ordinary cases truly somatic, for, in some instances, an inner and 

 verv distinct set exists, more worthy of the name of oral, homologically speaking. 



