THE CEPHALOTHORAX. 



153 



which lie immediately in front of the hindermost, there 

 is a s-mall round aperture for the attachment of the 



is^ 



Fig. Sd.—Astact/s fuviatiliii. — The cepbalothoracic sterna and the endo- 

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

 arthrophragms or partitions between the articular cavities for the 

 limbs ; ^.ff/?, cephalic apcdeme ; cf, cervical fold ; ejm. i,epimeronof 

 the antennulary somite ; h, anterior, and h', posterior horizontal 

 process of endopleurite ; lb, labrum ; m, mesophragm ; mt, meta- 

 stoma ; 7;, paraphragm ; I — XIV, cepbalothoracic sterna ; 1 — 14, 

 articular cavities of the cepbalothoracic appendages. (The anterior 

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

 the same plane with the remaining cepbalothoracic sterna ; in B 

 these sterna are not shown.) 

 8 



