S. I. Smith on American Crustacea. 169 



than in the corresponding leg of the left side, but are not as long as 

 in the female. 



The abdomen is not broader than in the male, but the margins are 

 slightly convex, it is not contracted at the sixth segment, and the 

 extremity is rounded. 



Length of cirapax, 51™™; breadth of carapax, S-S™™; ratio, 1 : 1-04. 



Pinnotheres Lithodomi, sp. nov. 



Female. The carapax, in the single specimen examined, is much 

 crushed out of shape, but the dorsal surface is smooth and naked. 



The raerus of the external maxilliped is broadest at the distal 

 extremity, and both margiiis are nearly sti'aight. 



The chelipeds are equal, smooth, and naked. The hands are cylin- 

 drical, and the fingers are short, nearly straight, the tips are slightly 

 hooked by each other, and the prehensile edge of the dactylus is 

 armed, near the base, with a small tooth, which fits a slight excava- 

 tion in the propodal finger. 



The ambulatory legs are very slender and wholly naked, except 

 the dactyli. In the first pair, the dactyli are very short and only 

 slightly curved ; in the second, they are considerably longer than in 

 the first, and nearly straight ; in the third, they are very long, being 

 nearly as long as the propodi, slender, and slightly curved ; and in 

 the posterior pair, they are about as long as in the second and are 

 ciliated along the posterior edges. 



Breadth of carapax, about, 4'""". 



The only specimen seen, was found in a specimen of Lithodomus 

 aristatus Forbes and Hanley which was in its excavation in the shell 

 of a Spondylus collected at the Pearl Islands by F. H. Bradley. 

 Although the specimen is very small, it has a large number of 

 eggs beneath the abdomen. 



OstraCOthereS Edwards. 



Ostracotheres politiis, sp. nov. 



Female, The carapax is depressed, naked, smooth, and shining. 

 The dorsal surface is flat and the borders are smoothly rounded. 

 There is a short median sulcus on the front, and a very slight U-shaped 

 one extending from the orbits to the middle of the carapax. The 

 front does not j^roject beyond the anterior margins. 



The external maxillipeds are smooth and almost entirely naked, and, 

 in fomi, are considerably like the figure of 0. affinis given by Edwards 

 (Annales des Sciences naturelles, 3""^ serie, Zoologie, tome xx, 1853, 



