CARCINUS. 
CANCER, Auctorum. 
CARCINUS, Leach. 
Antenna externa setace® articulis duobus primis majoribus, in oculorum cantho interno insert® 
Pedipalpi externi apice interiore truncato-emarginati. 
Pedum par anticum in®quale, didactylum, manibus externe glabris : paria 2, 3 et 4 subcom- 
pressa, unguibus quadratis longitudinaliter sulcatis : parquintum compressum, subnatato- 
rium, ungue compresso. 
Abdomen mabis 5-articulatum, articulo quarto transverso precedente vix angustiore : FceminjE 
7-articulatum. 
Testa diametro transverso submajore utrinque 5-dentata, margine antico semicirculari, orbita 
postice et inferne unifissa, cantho interno imperfecto. 
Oculi pedunculo angustiores. 
External antenn® setaceous, with the two first joints longest, inserted in the internal angle 
of the orbit. External pedipalpes with their internal apex truncate-emarginate. Anterior 
pair of legs unequal didactyle, their hands externally smooth ; second, third, and fourth pairs 
slightly compressed, with quadrate claws longitudinally sulcated : fifth pair compressed, with 
compressed claws. Abdomen of the male five-jointed, the fourth joint transverse, scarcely 
narrower than the preceding joint ; of the female seven-jointed. Shell rather broader than 
long, with five dentations on each side, the front margin semicircular : orbit behind and 
beneath with one fissure, the internal canthus imperfect. Eyes narrower than their peduncles. 
One species only of this Genus is known. 
