THE CEPHALOTHORAX. 



153 



which lie immediately in front of the hindermost, there 

 is a small round aperture for the attachment of the 



JSV 



Fig. 39. — Astac7is Jli(viatilis.— The ce\)ha\othoracic sterna and the endo- 

 phrag-mal system ( x 2). A, from beneath ; B, from above. <7, a', 

 arthrophrag-ms or partitions between the articular cavities for the 

 limbs ; <:'.c/7;, cephalic apodeme ; cf, cervical fdld ; cjfti. 1, epimeron of 

 the antennulary somite; A, anterior, and 7t', posteri<>r horizontal 

 process of endopleurite : lb, labrum ; m, mesophrag-m ; mt, meta- 

 stoma ; p, paraphragm ; 7 — XIV, cephalothoracic sterna ; 1 — 14, 

 articular cavities of the cephalothoracic appendages. (The anterior 

 cephalic sterna are bent downwards in A so as to bring- them into 

 the same plane with the remaining cephalothoracic sterna ; in B 

 these sterna are not shown.) 



