146 WEST AMERICAN SHELLS 
Onchidélla borealis, Dall, the Northern Onehi- 
della, is but little larger than the last. Surface 
black, with dots and streaks of yellowish white, 
foot hght colored, also muzzle and tentacles. Al- 
aska, (Sitka), and Vancouver Island. 
The Auriculide, or FEar-shells, inhabit salt 
marshes and love brackish water. They have 
strong shells with short spires, and narrow, ear- 
shaped apertures. The first of our species is 
named Alexia myosotis, Drap., the Mouse-ear Al- 
exia. The shell is brown and spindle-shaped, simi- 
lar in form and size to a small grain of wheat. 
Probably it was imported from Europe, as it is 
found around Atlantic seaports, and also near 
San Francisco. 
Carychium exiguum, var. occidentale, Pils., the 
Western Carychium. Shell minute, distinetly coni- 
eal, whitish, with an evident spire of fine rounded 
whorls. Aperture nearly circular, columella with 
a distinct tooth. From Portland, Oregon. The 
shell is about one-sixteenth of an inch in length; 
it is found about wharves and on stones which are 
sometimes covered with tide water. 
Figure 125 gives a good idea of the shell 
of Melampus olivaceus, Cpr., the Olive Ear- 
shell. The shell is pear-shaped with a short 
spire and a long, narrow aperture. There 
are two folds on the columella. Dark brown, 
with lighter stripes and bands; length, half an 
inch; southern. It occurs plentifully on salt mud- 
flats. 
Pédipes unisulcatus, J. G. Cooper, the Fur- 
rowed Pedipes. Spire short, body-whorl large 
Fig. 125 
