MASKED CRAB. 159 



DEC APOD A. CORYSTIDM. 



BRACHTURJ. 



MASKED CRAB. 



Corystes Cassivelaunus. 



Cancer cassivelaunus, Pennant, Brit. Zool. iv. t. vii. p. G. 

 „ „ Herbst, 1. 1. xii. f. 72. Mas. 



„ pcrsonatus „ t. xii. f. 71. Fern. 



Alhunea. dentata, Faur. Suppl. 398. 



Cori/stcs detitatus, Latr. Hist. Nat. des Crust, et Insect. VI. p. l'2-2. 



Edw. Hist, des Crust. II. p. 148. Couch, Corn. 

 Faun. p. 74. 

 „ Cassivelaunus, Leach, Edinb. Encycl. VII. p. 395. Mai. Brit. t. i. 



The carapace in this species is longer than it is broad, in 

 the proportion of nearly three to two ; convex, with the 

 regions somewhat distinctly marked, having a groove sur- 



