of the Pacific Shores of North America. 447 
tropics must swarm with Crustacea of the higher orders, the 
„Species of which are as yet entirely undetermined. With- 
out, therefore, attempting to generalize upon so imperfect 
data, we may notice a few facts with regard to the character 
of the Crustacean fauna, which are so prominently marked 
that they will be but little affected by future discoveries. - 
The tribe Ozyrhyncha is very numerously represented in 
the rocky fiords of the upper coast, and a predominance of 
deep-water forms may be observed, the genera of which are 
mostly peculiar to this region. The restricted genus Cancer 
(Platycarcinus, M. Edw.) is remarkably well represented 
here, by four species, very abundant in individuals, and 
Which are in fact the most common crabs known. On the 
other hand, with the exception of a single species of Ozius, 
no other examples of the Cancrinea, elsewhere so numerous, 
have yet occurred ; and it is indeed singular that the sandy 
Shores of California, so well adapted to Lupa and its allies, 
should have as yet furnished no species of the Portunide. 
In this point a striking difference is shown between the 
Marine fauna of this and the eastern coast, where such 
forms are abundantly distributed. 
The chief and most noticeable feature, however, which 
Sigpncee gives a peculiar character to the Decapoda of the 
| Western coast, is the remarkable development of the 
odina. But few species of the rare and curious crabs 
of this family, all denizens of deep water, were until recently 
own, one of which (the only one described in the * His- 
toire Naturelle des Crustacés,”) is found in the North Atlan- 
tie, one in the Antarctic Ocean, and two in the seas of 
Japan and Kamtschatka. Within the past ten years, how- 
*ver, no less than nine additional species have come to light, 
nearly all'of which were found on the shores of California, 
Oregon, and Russian America. Among these are some 
&igantic and representative forms which tend greatly to 
enlarge our views of the extent, importance, and relations of 
= group. For our knowledge of these interesting Crusta- 
feans, we are chiefly indebted to Branvt of St. Petersburg. 
