MARINE UNIVALVES 175 
Chrysodomus magnus, Dall, the Great Spindle- 
shell, Figure 169, grows to a length of three inches. 
The shell is rather thin, the whorls flattened, with 
a strong keel at the shoulder, and there is a thick, 
bearded epidermis. This fine shell was dredged 
in Bering Sea. 
Figure 170 represents a magnificent shell 
from the waters around the Aleutian Islands, 
and other regions 
in that vicinity. Its 
name is Beringius cre- 
bricostatus, Dall, the 
Ribbed Bering-shell. It 
grows to a length of 
five inches. The color is 
white, with a darker 
flush in the throat, while 
the epidermis is bright 
vellowish. 
Beringius friélei, Dall, 
Friele’s Bering - shell, 
Figure 171, is another 
large shell of this spe- 
cles, which bears the 
name of the great navi- 
gator. Vitus Bering 
was a Dane by birth, 
but he entered the Rus- 
