[485] INVERTEBRATE ANIMALS OF VINEYARD SOUND, ETc. 191 
of these localities in summer. In April, May, and June, the cod and 
haddock resort in large numbers to the banks and refs off Stonington, 
Watch Hill, No Man’s Land, and other similar places, but are quite 
unknown there later in the summer. 
In consequence of the varying temperatures of the currents which 
alternately pass over certain of these localities, there isa very peculiar 
admixture of northern and southern species, side by side. This is par- 
ticularly the case on the reefs between Watch Hill and Fishev’s Island, 
where the southern Astrangia Dane is associated with the northern 
Alcyonium carneum, Cribrella sanguinolenta, and many other northern 
forms. 
The temperature of the bottom-water during the last of August and 
first of September was found to vary from 57° F, to 63°, in sixteen to 
twenty-nine fathoms off Martha’s Vineyard and Buzzard’s Bay, (see 
chart.) The surface temperatures were at the same time 62° to 64°, and 
occasionally as high as 67°, when affected by warmer currents. 
IV. 1.—SPECIES INHABITING ROCKY SHORES OF THE OPEN COAST. 
The principal localities under this head at which we have made col- 
lections are No Man’s Land, Cuttyhunk Island, Gay Head, and Watch 
Hill, Rhode Island. Dr. J. E. Leidy has published a partial list of the 
species found at Point Judith,* and we have more or less information 
concerning the fauna of several other similar localities. In all these 
places the assemblage of animals is nearly the same, and in general not 
very different from what we find on the rocky shores of the sounds and 
bays, (see p. 303.) A large part of the species of these shores have, 
therefore, already been mentioned in connection with the fauna of the 
bays and sounds. 
There are, however, many species that are characteristic of the latter, 
which are found but rarely, or not at all, on the colder and more ex- 
posed outer shores; and these are characterized by the abundance of 
some northern species which are rare or wanting on the inner shores, or 
which occur there only in winter. 
Among the most abundant species of shells are Purpura lapillus, (p. 
306, Plate X XI, figs. 118, 119;) Littorina palliata, (p. 305, Plate XXIV, 
fig. 1388;) L.rudis, (p. 305, Plate XXIV, fig. 137 ;) Aemewa testudinalis, 
(p. 307, Plate XXIV, figs. 158, 159;) and Lacuna vineta, (p. 305, Plate 
XXIV, fig. 139,) all of which occur adhering to the rocks or algie, even 
in the most exposed situations. These are all hardy northern species, 
which extend their range to Greenland or beyond, and although all of 
them are to be found, more or less frequently, on the inner shores, they 
are there less abundant and generally of smaller size. The Dittorina 
palliata is extremely abundant on the Fucus, and individuals were found 
at Watch Hill, copulating, April 12. The Lacuna vincta breeds still 
* Journal of the Academy of Natural Sciences of Philadelphia, 2d series, vol. iii, 
1855. 
