Pacific Shores of North America. 11 



lis longis ; articulus immobilis Iatus, fere quadratus, apice externo spina acuta 

 lateral iter porrecta armato. Epistoma magna, subtrapezoidalis. Maxillipedes 

 externi fere ut in Pisa ; apice interne- articuli secundi valde productA et rotun- 

 data. Pedes subcylindrici, secundi paris longiores ; tarsi breves non spinulosi ; 

 digiti primi paris maris fiBminasque margine interno toto denticulato. Abdo- 

 men 7-artieulatum. 



This genus is proposed for the reception of two new 

 species of Maioid crabs, which, though differing from each 

 other considerably in the characters of the surface of the 

 carapax, and some other points, yet are so closely allied in 

 the structure of the orbits and antennae that they cannot be 

 generically separated. They unite the characters of several 

 generic groups, so that their position is somewhat doubtful, 

 although probably among the Pisince. The deflection of 

 the rostrum is quite characteristic, but this feature is much 

 less developed in one species than in the other. The eyes 

 are short, and do not reach the tip of the post-orbital spine. 

 The genus will be perhaps best characterized by a com- 

 parison with others. From Pisa, which it resembles in the 

 shape of the carapax, it differs in the less excavated orbits, 

 and single supra-orbital fissure, the want of spinules on the 

 tarsi, and the much broader basal article of the external 

 antenna?. This latter character also separates it from Herb- 

 stia and Halimus. From the Chorinince it may be distin- 

 guished by the non-concealment of the external antennas, 

 and the shorter and broader rostrum. It is allied to Para- 

 micippa in the deflection of the rostrum, but differs in the 

 longer epistome, and the inferior position of the external 

 antennas. The cavities of the eye-peduncles are less tubular 

 than in Pericera, the eyes being retractile. Perinea has a 

 shorter carapax and a much shorter rostrum, leaving the 

 external antennae considerably exposed. 



This genus, like several others of the tribe, seems to be 

 peculiar to this coast. The species are crabs of large size. 



