ur, 



ZOOLOGY. 



those which are formed for running, the crabs, for example, 

 the abdomen is very short, has no terminal fin, and is curved 

 under the thorax. 



574. The stomapoda have also the eyes carried on move- 

 able peduncles, the thorax covered entirely or partly by a 

 carapace, and the limbs cylindrical ; but their branchiae are 

 not enclosed in the cavities of the thorax, but float under the 

 abdomen, or are altogether wanting. The squilla (Fig. 429), 

 of which we have already spoken, belongs to this order. 





Fig. 432. Anilocra. 



Fig. 433. Liranadia. 1 



575. Ill the division edriopthalmia, the head is distinct 

 from the thorax, and this last part of the body is composed 

 of a series of seven rings, each carrying a pair of limbs. 

 Thus, as we have already said, there is not any carapace, the 

 eyes are not pedunculated, there are no branchiae, properly so 

 called, but the respiration is performed by means of various 

 appendages borrowed from the locomotory apparatus. Na- 

 turalists arrange under this group, 



1. The amphipoda, which have the abdomen well developed, 

 and carry under the thorax a double series of respiratory 

 vesicles, formed by the internal branchiae of the liinbs. The 

 prawns of rivulets and the talytri (Fig. 146) offer us t lie-so 

 characters. 



2. The loemodipoda, which resemble the pn-iveliiig in the 

 disposition of the organs of respiration, but whii-li have only 

 a rudimentary abdomen. 



* One of the valves of the carapace has been 



