136 CRUSTACEA. 



of abdomen very large and shield-like. Inner 



antennae small, but distinct 



Appendages of last false feet very large, 

 plate-like, covering, as an operculum, the 

 whole under-surface of the abdomen ; not 

 prolonged behind. Last segment of abdo- 

 men very large and shield-like .... Idoteada. 



FAMILY I. ONISCID^E. 



Lygia (Fabr.). Basal joint of last false feet 

 lengthened, and terminating in two very long 

 styles. 



L. oceanica. Fig. 241 ; n. s. 



FAMILY II. ASELLIDJE. 



Limnoria (Leach). Abdomen of six segments ; 

 antennae sub-equal. 



L. terebrans. Fig. 242 ; mag. . 



Jaera (Leach). Abdomen of one segment; outer 

 antennae much longer than inner. 



J. albifrons. Fig. 243 ; mag. ^. 

 Kroyeri. 



Oniscoda (Latr.). Last false feet prolonged into 

 two styles ; all the true feet alike. 



0. maculosa. Fig. 244 ; mag. -J. 



Apseudes (Leach). First feet armed with a two- 

 fingered claw; second feet large, flat, and not 

 resembling the following feet. 



A. talpa. Fig. 245 ; mag. &. 



Tanais (M.-Edwards). First feet two-fingered; 

 second feet fanged; antennae very short, with no 



