212 N'otes on Worth American Crustacea. 



"well areolated, the anterior branchial lobule being circumscribed. 

 Latero-inferior regions granulated. Front depressed and transversely 

 channelled, nearly straight in a view from above, but strongly bidentate 

 at the middle in a front view ; teeth obtuse. Basal joint of the external 

 antennae narrow and projecting, being jammed in the inner angle of the 

 orbit. External maxillipeds more or less pubfescent ; meros rather 

 deeply bisulcated, and conspicuously notched anteriorly at the efferent 

 aperture. Color dark reddish. Length of carapax, 1.65 ; breadth, 1.1 

 inch. 



It has some resemblance to 0. verreauxii, but is broader, 

 more deeply areolated, and rngose, almost vermiculated anteri- 

 orly. The basal joint of the autennse also, in O. verreauxii, is 

 much broader and more flattened. 



It was found in considerable numbers at Cape St. Lucas, by 

 Mr. Xantus. 



A species closely allied, and if not identical with this, is 

 found at the island of Jamaica. It has, however, a moi-e acute 

 antero-lateral margin. 



]>aii*a aiiicricana, nov. sp. 



Closely allied to D. perlata, differing only in the fingers, 

 which in our species are not spoon-shaped but acuminate, and 

 in the existence of tufts of setse between the tubercles of the 

 carapax. Length of the carapax in the male, 0.8 ; breadth, 

 1.15 inch. 



This species affords another instance of the slight value of 

 the degree of excavation of the finger tips as a distinguishing 

 character. It should scarcely be used for families, when in this 

 and some other instances it is not even of generic importance. 



We have here removed the genus Daira from the vicinity of 

 Ghlorodius to that of Pilumnus^ in view of the strong ridge 

 upon the palate, and some other characters of nearly equal im- 

 portance. Daira is especially characterized by the notch of 



