ROCINELA. 289 



ISOPODA. 



NORM A LI A. 



Genus ROCINELA. (Leach.} 



Generic character. Eyes very large and convex, converging 

 anteriorly and nearly uniting in the middle of the forehead, 

 which is produced into a conical point concealing the base of 

 the upper antennae ; first and second joints of the latter 

 cylindrical and much more slender than those of the lower 

 antennae, which are nearly one-third of the length of the body. 







As our generic and specific descriptions are made from 

 Dr. Leach's original type of R. Danmoniensis (the only 

 species which he inserted in the genus), we are able to 

 ascertain that M. Milne Edwards has misconceived 

 Leach's views (which is not indeed surprising, as the very 

 short and unsatisfactory descriptions given by the latter 

 would scarcely afford a definite idea of its characters). 

 We consequently find that the genus thus named in M. 

 Milne Edwards's great work consists of species of ^Ega, 

 with the eyes confluent and the basal joints of the upper 

 antennae rather more slender than in the typical JEgae ; 

 but when we take into consideration, that the front of 

 the head in Leach's type is produced into an obtuse 

 conical point projecting over the base of the upper an- 

 tennae, which are much more slender than the base of the 

 lower antennae, the latter being also more than one-fourth 

 of the length of the entire animal ; that the pleon is as 

 wide as the pereion, the anterior segment being, however, 

 very short, and abbreviated at the sides, which neverthe- 

 less terminate in an acute point ; and that the three fol- 



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