DEC APOD A. LEUCOSIADM. 



BRACHYURA. 



GENUS EBALIA, LEACH. 



CANCER, Pennant, Montagu. 



LEUCOSIA, Leach. 



EIJALIA, Leach, Edwards, &c. 



Generic Character. External antennae extremely minute, in- 

 serted in the inner canthus of the orbit. Internal antenna; lying 

 in oblique fossae, which are entirely separated by a small process 

 of the epistome, and concealed by the front. External pedipalps 

 elongato-triangular, reaching forwards to the margin of the epi- 

 stome ; the internal footstalk gradually acuminated, the third joint 

 internally palpigerous. Anterior legs large, equal, the hand in- 

 flated, those of the male larger than those of the female ; the other 

 legs shorter than the first pair, diminishing gradually in length, 

 terminating in a slightly curved, rather strong claw. Abdomen 

 seven-jointed, but with several of the middle joints confluent ; 

 that of the male narrow, gradually diminishing from the third 

 joint : of the female very broad, the last joint very small, abruptly 

 narrower than the preceding. Carapace rhomboidal, with the 

 angles more or less truncated or rounded ; front produced, ele- 

 vated. Eyes very small. Orbits with two small fissures on the 

 superior margin. 



OF this genus, which forms the English representative 

 of the family Leucosiada, there are three distinct species 

 found on our coasts. These are sufficiently distinct in 

 several very tangible and essential characters ; and I 

 am surprised to find that Dr. Milne Edwards should con- 

 sider them merely as varieties. The distinctions will be 



