brane 
[491] INVERTEBRATE ANIMALS OF VINEYARD SOUND, ETC. 197 
MOLLUSCA. 
Gastropods. 
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Sycotypus canaliculatus .... 399 | C. unguiformis......... aee «6804 
Tritia trivittata............ 354 | Lunatia heros...........-- 490 
Crepidula fornicata......... 355 | Neverita duplicata ........ 490 
Lamellibranchs. 
Page. Page. 
Ensatella Americana ....... 490 | Mya arenaria .........--.. 490 
Siliqua costata............. 426 | Mactra solidissima........ 490 
RADIATA, 
Echinoderms. 
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Leptosynapta Girardii...... 490 | Echinarachnius parma..... 490 
IV. 3.— ANIMALS INHABITING ROCKY BOTTOMS OFF THE OPEN COAST. 
The fauna of the rocky bottoms in these outer waters is rich and in- 
teresting, and decidedly northern in character, though there is usually 
an admixture with southern species. 
The principal localities where dredgings were made on this kind of 
ground are: First, off Gay Head and Devil’s Bridge, at localities marked 
on the chart, 53, a, b, ¢, d; 55, a, b, ¢; 56, a, b,c, d; 57, a, b, e, dj 58, 
a, b,¢; 59, a,b, e; 60, a,b, ¢; 61, 4, b, e; 62, a,b, ¢3 68, a,b; 83, a, b,c. 
Second, between Gay Head and No Man’s Land, and to the westward of 
the latter island, at localities 82, a,b ; 84, a,b, c,d; at these localities cod 
are caught in the spring. Third, on and about the rocky reef extending 
from Watch Hill, Rhode Island, to Fisher’s Island, and forming, in part, 
the physical boundary of the eastern end of Long Island Sound; this 
is also a locality where cod and haddock are caught in spring. The 
dredgings at this place were made by Professor D. C. Eaton, Mr. C. A. 
Burt, and myself, April 13, 1873. Fourth, a locality off Cuttyhunk Island, 
where dredgings were made, April, 1872, by Mr. T. M. Prudden, Mr. T. 
H. Russell, and others. : 
The four localities named are characterized by a similar fauna, 
but each one yielded some species not found in the others, though 
more numerous dredgings might have revealed them. The reef off 
Watch Hill is of peculiar interest on account of the singular blending 
of the northern and southern faunze at that place, as mentioned above, 
It seems to be nearly at the extreme western range of many nofthern 
species, though some of them may occur sparingly in certain favorable 
localities still farther westward, in Long Island Sound itself. Many 
northern algie were also collected there by Professor Eaton, in abund- 
