of the Pacific Shores of North America. 487 



chiefly the anterior one, while it is smooth in the middle ; — 

 in our species it is generally everywhere rugose, except at 

 the postero-inferior wings, and much more so anteriorly 

 than in the other species. In female individuals of equal 

 length, the terminal segment of the abdomen is one sixth 

 longer in H. talpoidea than in H. analoga. Finally there are 

 slight differences in the details of the feet and antennae, not 

 as well marked, however, nor as constant as those of the 

 carapax. One of the most prominent of these is in the 

 spines of the acicle or appendicular scale of the outer anten- 

 nae, which in our species are somewhat longer, more slender, 

 and more curved, than in the eastern one. 



Compared with H. emerita, the teeth of the frontal mar- 

 gin of the carapax are found to be much less acute than in 

 that species ; the spines of the acicle are not as long, and 

 are curved inward instead of outward. 



It is of a bluish or cinereous color above, and yellowish- 

 white below ; the fringing hairs are mostly black. The 

 dimensions of a female specimen from Tomales Bay are 

 as follows : length of carapax, 1.19 ; breadth, 0.91. 



It inhabits sandy beaches on the open coast. 



Hab. Tomales Bay, (Samuels ;) near San Francisco, 

 (Trowbridge;) Monterey, (Taylor;) and Mazatlan, (Ver- 

 reaux.) 



Mus. Bost. Soc. ; Phil. Acad. ; Smithsonian ; Paris ; 

 Acad. Petrop. 



Tkibe GALATHEIDEA. 



GRIMOTEA GREGARIA. Leach. 



Galathea gregaria, Eabr. 



Grimotea gregaria, Leach ; Diet, des Sci. Nat. xviii. 50. Owen ; ZoOl. of 



Beech&Js Voy. p. 87. See figure in Dana's Report on the Crustacea of the 



Exploring Expedition, Atlas, PI. XXXI. f. 1. 



A pelagic species, found swimming at the surface off' the 

 coast of California by the naturalists of the " Blossom.'* 

 Mus. Zool. Soc. of London. 



