14 Crustacea and Eckinodermata of the 



sternal plastron and abdomen in the male are transversely 

 grooved with deep channels corresponding in number to the 

 articulations. The color beneath the pubescence is bluish- 

 white, the rostrum, spines, and feet being of a bright car- 

 mine hue. 



Length of carapax, $ 3.45 



Greatest width 2.30 



Length of rostrum 0.67 



Distance between tips of prseorbital spines .... 0.82 



• l " anterior spines of branchial region . 1.40 



Length of 1st pair of legs 3.50 



" " 2d 4.40 



Found at the island of San Miguel, off the coast of Cal- 

 ifornia, near San Pedro. This is another of the novelties 

 for which we are indebted to that indefatigable observer, 

 Lieut. Trowbkidge, who, though devoting his chief atten- 

 tion to the Vertebrata, has succeeded in making collections 

 of the lower forms of animal life, of greater extent and inter- 

 est than has any other student of Californian Zoology. 



Mas. Smithsonian. 



libinia aitinis. Randall. 



Libinia affinis, Randall ; Jour. Acad. Nat. Sri., Philad. viii. 107. Gibbes, 

 Proc.Am. Assoc. 1850, p. 170. 



This species is rare, Nuttall's specimen being the only 

 one yet found. It is very closely allied to L. canaliculata of 

 the eastern coast, but differs in its less convex carapax and 

 smoother hand. 



Upper California, (Nuttall.) 



Mus. Phil. Acad. 



chorilia loxgipes. Dana. 



Chorilia longipes, Daxa ; U. S. Expl Expedition, Crust, i. 91 ; PI. I. f. 5. 



This species may be distinguished from the other Oxy- 



