158 



CRUSTACEA. 



Family I. Corystim:. 



Corystes (Leacli). Carapace much longer than 

 wide, ovate, cut with few teeth at the sides ; outer 

 antennae together forming a tube. 



C. Cassivelaunus. Fig. 298 ; i n. s. 



Atelecyclus (Leach). Carapace nearly circular, 

 evenly convex, cut with many teeth. 



A. heterodon. Fig. 299 ; i n. s. 



298 



299 



301 



302 



304 



TMa (Leach). Carapace heart-shaped, narrowed 

 behind, arched from side to side only ; front forming 

 a broad plate concealing the eyes. 

 T. polita. Fig. 300 ; n. s. 



