66 HISTORY OF BRITISH CRUSTACEA. 



Gen. 2-2. CORYSTES, Latr. 



Carapace much longer than wide, with a few teeth ; front 

 lamellar, forming a triangular beak. Outer antennae very 

 large, much longer than carapace, and furnished on upper 

 and lower margins with a row of long hairs. Fore legs of 

 male very long. 



Mr. Couch thus refers to the use of the long antennae. 

 He says that our species burrows in the sand, leaving only 

 the ends of its antennas projecting above the surface; he 

 supposes that these organs are of some use beyond their 

 common office of feelers, perhaps assisting in the process of 

 excavation. lie remarks, i( When soiled by labour, I have 

 seen the Crab effect their cleaning, by alternately bending 

 the joints of their stalks, which stand conveniently angular 

 for this purpose. Each of the long antennae is thus drawn 

 along the brush that fringes the internal face of the other, 

 until both are cleared of every particle that adhered to 

 them."* 



Corystes Cassivelaunus, Penn. sp. Pennant's Long- 

 armed Oral. (Plate IV. fig. 5.) — Carapace swollen, with two 

 irregular waving grooves, which to the fanciful eye seem to 



* Cornish. Fauna, p. 7-i. 



