the Geographical Distribution of Marine Species. 315 
The southern of these regions averages five degrees in width. ~ 
The eastern limit on the African coast is sixteen to eighteen de- 
grees to the north of the western on the South American coast. 
Atlantic Temperate Regions, between 62° and 56° F.—The 
north ‘Temperate Region is but a narrow strip of water on the 
west, terminating at Cape Hatteras, and having no place on the 
coast of the United States. ‘To the east it widens, and embraces 
Madeira lies upon its southern limit. It is, therefore, natural, 
that the same species should occur at the Azores, Madeira, and 
on the African coast, and be excluded wholly from the Atlantic 
coast of Europe. This according to Prof. Forbes, is the fact with 
the Littorina striata, besides other species. The coasts of Por- 
tugal and the Azores are in different regions. 
The South Temperate Region extends to Maldonado at the 
mouth of the La Plata, from near the parallel of 30°; along the 
African coast it reaches over more than twice the number of de- 
grees of latitude, to within five degrees of Cape ‘Town. 
Atlantic Subtemperate Regions, between 56° and 50° F.— 
The northern of these regions, like the preceding, can not be 
distinguished on the coast of the United States, as the lines of 
50° and 56° F. with 62° fall together at Cape Hatteras. On the 
eastern side of the Atlantic, it occupies the coast of Portugal to 
latitude 42° north, having a width of five degrees. It thus cor- 
responds on this coast to the so-called Lusitanian Region. 
The southern includes the mouth of the La Plata on one side, 
pe Negro for about five degrees, and passes wholly to the south 
of Africa. 
Atlantic Subfrigid Regions, between 44° and 35° F.—The 
coast of Massachusetts, north of Cape Cod, of Maine and New- 
foundland, and all Northern Britain, the Orkneys, Shetlands, and 
Faroe Islands, pertain to the northern Subfrigid Region ; while 
the southern, includes the Falklands, Southern Patagonia, and 
uegia. 
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