220 L/EMODiPODA. 



could have made signs of their happiness, they could not have done 

 it more intelligibly/' 



In order to leap, they bend the appendages to their tail under 

 their body, and then forcibly straighten them as though they were 

 let go by a spring, exactly like the Podurse or Spring-tails among 

 insects. 



FOURTH ORDER OF CRUSTACEA. 

 . LUEMODIPODAJ (Neck-footed Crustaceans). 



The body of these creatures is generally slender 

 and elongated, and composed of eight or nine seg- 



G. 168. CAPKKLLA. 



ments. The four front legs, which are always the 

 largest, are attached to the neck, and are terminated 

 by a prehensile hook. The hinder legs are shorter, 

 and their armature more feeble. The females carry 

 their eggs between the second and third segments of 

 the body, in a little pouch formed of scaly pieces. 

 The species are all marine. Some of them live 

 amongst sea weeds, upon which they crawl, much 

 after the manner of the caterpillars called loopers. 

 They are, however, likewise able to swim. Others 

 are found to live parasitical] y upon whales, a cir- 

 cumstance which has obtained for them the name of 

 whale-lice. They have likewise been seen on the 

 mackerel. 



* \ai/u,6s, laimos, the throat ; 5is, dis, twice; ir6vs-Troti6s, pous-podos, 

 a foot. 



