170 WEST AMERICAN SHELES 
Figure 160 represents two specimens of Buc- 
cinum angulatum, Gray, the Angled Whelk. The 
pictures are none too large, for the shells are 
strong and robust. Both of them represent 
females, however, and the shells of the males of 
the same species are materially smaller. This 
species lives on the shores of the polar sea, near 
Bering Strait, and in the Arctic Ocean. It repre- 
sents a decidedly frigid type. 
Buccinum aleuticum, Dall, the 
Aleutian Whelk, Figure 161, 
has a thin, six-whorled shell, of 
a pinkish color with a white 
pular. It is covered with a thin 
epidermis, somewhat bearded. 
The sculpture consists of fine, 
close-set grooves, with spaces 
between them. The figure is 
slightly magnified. 
Buccinum percrassum, Dall, 
the Thick-shelled Whelk, is Fig. 161, x 3 @) 
shown in Kigure 162. This 
solid little shell is found in the 
waters that bathe the shores of 
Bering Island, a name _ that 
makes us think of sealskins 
and refrigerators. The oper- 
culum is remarkably distinct, 
and the shell is decidedly thick 
and solid. 
Two specimens of Buccinum 
castaneum, Dall, the Chestnut 
Fig. 162 (*) 
