40 
S. I. Smith — Crustaceans of the Atlantic Coast. 
In habits this species differs very greatly from irrorcitus. The 
best opportunities which I have had for observing it were at Peak’s 
Island, in Casco Bay, August and September, 1873. Empty carapaces, 
chelipeds, etc., of borealis were at first found in abundance scattered 
along the outer shores, far above the action of the waves, where they 
had evidently been carried by gulls and crows, and were also found 
in considerable numbers half a mile from the shore in a forest of 
coniferous trees thickly inhabited by crows. For several weeks no 
living specimens of borealis were discovered, although the irroratus 
was found living in abundance all about the island, without, however, 
its remains scarcely ever being found scattered about with those of 
borealis. The borealis was finally discovered in abundance, at low 
water, on the exposed and very rocky shores of the northern end of 
the island. At this locality, between eighty and ninety specimens, 
all females and many of them carrying eggs, were obtained in a 
single morning. They were all found in situations exposed to the 
action of the waves and were either resting entirely exposed upon 
the bare rocks and ledges, or clinging to the sea-weeds in the edge 
of the waves or in the tide-pools. They were never found concealed 
beneath the rocks, where, however, irroratus abounded. It is a much 
heavier and more massive species than the irroratus and is conse- 
quently much better adapted than that species to the situations in 
which it is found. So many individuals falling a prey to birds is 
evidently a result of the habit of remaining exposed between tides, 
although the heavy shell must afford much greater protection than 
the comparatively fragile covering of irroratus would afford to that 
species if similarly exposed. The borealis was also found at a some- 
what similar locality, but more exposed to the sea, on Ram Island 
Ledge, a low reef open to the full force of the ocean. One specimen 
of moderate size was dredged in the ship channel between Peak’s 
Island and Cape Elizabeth, in ten fathoms, rocky and shelly bottom, 
and specimens were several times captured in “ lobster-traps” set, at 
a depth of eight or ten fathoms, among rocks. Specimens were also 
several times found in stomachs of the cod taken on the Cod Ledges. 
In the vicinity of Vineyard Sound, this species was not infrequently 
found thrown upon sandy beaches, but never upon beaches very far 
removed from rocky reefs. The following are the localities where it 
was seen in greatest numbers : along the sandy beach of Martha’s 
Vineyard from Menemsha Bight to Gay Head ; the rocky island of 
Cuttylmnk; and the rocky outer shores of Nomansland, where dead 
specimens were found in considerable abundance. 
