426 



SPHiEROMID.E. 



ISOPODA. 

 NOBMALIA. 



iiPHJEROMIDjE. 



CYMODOCEA TRUNCATA. 



Specific character. Pleon slightly granulated ; fourth segment with tuo 

 small tubercles in the middle of the hind margin ; terminal segment with 

 two larger dorsal tubercles, followed by a central oval, very setose tubercle, 

 and three terminal spines, which are truncated. 



Length, five-twelfths of an inch. 



Oniscus truncatus. Moktagu MSS. in Brit. Mus. 



Cymodocea truncata. Leach, Edinb. Enc. vii. p. 433. Trans. Linn. Soc. 



xi. p. 303. Suppl. Enc. Brit. i. 427. Dictionn. Sci. 



Nat. xii. p. 343. Samouelle, Ent. Compend. p. 108. 



Desmarest, Cons. Crust, p. 297. Milne Edwards, 



Crust, iii. p. 214. W. Thompson, in Ann. Nat. 



Hist. XX. p. 246. White, B. M. Cat. Brit. Crust. 



p. 76. Pop. Hist. Brit. Crust, p. 240. Gosse, 



Man. Mar. Zool. 1, fig. 236. 



Our figure of this species is made from Dr. Leach's 

 typical specimen preserved in the British Museum. It 

 is very nearly allied to the following species, but it is 

 much less rugose, and the form a)id size of the lateral 

 appendages of the tail are different in the two species. 



