176 Geographical Distribution of Crustacea. 
lantic east of the West Indies contains no islands in the Torrid 
zone, besides St. Helena, Ascension, and the Cape Verdes, all 
of which are of small size. 
Again in order to compare the coasts of America and Europe, 
we must observe that the warm temperate region is represented 
along the former by a small district from Northern Florida to Cape 
Hatteras, while this region does not reach at all the latter, and 
only the Canaries in the Eastern Atlantic are within it. 
over, the temperate and subtemperate regions have no existence 
on the North American coast at Cape Hatteras; while on the Eu- 
ropean side, the former embraces the larger part of the Mediterra- 
nean, and a portion of North-western Africa, and the latter includes 
the Atlantic coast of Portugal. But north of Cape Hatteras, the 
coast of America is rightly compared with that of Europe, north 
of Portugal. 
To compare the coast of Asia and Europe, we first observe in 
the same manner the temperature regions, There is in fact a 
striking similarity with the coast of the United States. Yet, the 
torrid and subtorrid regions are confined to limits much nearer the 
equator ; and the warm temperate, although embracing as many 
degrees of latitude as the warm temperate on the United States, 
does not, on the China coasts extend farther north than the sub- 
torrid region of the Florida coast. The temperate region hardly 
has a place on the coast of China, while the subtemperate occu- 
pies the Yellow Sea. North of this Gulf, the coast corresponds 
mostly with the coast of the United States, north of Cape Cod. 
It is unnecessary to adduce other explanations, as the chart fur- 
nishes all that is needed for a ready comparison between the dif- 
ferent coasts. 
The propriety of uniting in one kingdom both coasts of Amer- 
ica, the eastern and western, and thus shutting off the latter from 
the great Pacific Ocean, may at first appear unnatural. “Yet it is 
supported by all facts bearing on the subject. There are no spe- 
cies known to be common to Western America and the Middle 
Pacific, excepting two or three cosmopolites. Moveover, the gen- 
era are to a great extent distinct, and where so, they often occut 
on both sides of the continent. The genera of Podophthalmia 
peculiar to America are mentioned on a preceding page, and also 
the particular coast on which they occur. 
_A review of some of the facts will exhibit in a strong light the 
zoological resemblances of the two sides of the continent. 
Of Cancer, there are four species found on the west coast of 
South America, three on the west coast of North America, and 
two on the east coast of North America. : 
f Hepatus, there is one species common to the West Indies 
and Brazil, a second, found at Rio Janeiro ; a third at Valparaiso, 
Chili; a fourth on the Carolina coast. 
