124 WEST AMERICAN SHELLS 
species, is Oreohélixn idhoénsis, 
Newe., the Idaho Snail, a view of 
which is shown in igure 104. The 
shell is small, strong, and white. The 
whorls are crossed by many blunt 
ribs. Its diameter is about half an inch. 
Oreohélia élrodi, Pilsbry, Elrod’s Snail, is 
another of this series, and is found in the Mission 
Mountains, Montana. The last whorl of this shell 
has an acute, peripheral keel, for which reason it is 
believed by Dr. R. E. C. Stearns to be identical 
with the California species, Epiphragmophora 
circumearinata. Others doubt the identity, though 
the resemblance is very great. The shell is nearly 
an inch in diameter. 
Oreohélia cockeréll, Pils., Cockerell’s Snail, 
is found in New Mexico and Colorado. It has the 
general shape of P. striatella, but is far smoother. 
The shell is thin, greenish, streaked with light yel- 
low; diameter about 6mm. 
Patula solitaria, Say, the Solitary Snail, is es- 
sentially an eastern species, being particularly 
abundant near the Ohio River. Nevertheless it is 
found in Idaho, Oregon and Washington. The 
shell is low, conical, has five whorls, a large, cir- 
cular umbilicus, and a sharp outer lip. It is of a 
yellowish brown color, and the whorls are marked 
with two dark brown bands with a lighter stripe 
between them. Its diameter is three-fourths of an 
inch or more. 
Pinctum conspéctum, Bland, the Dial Dot-shell. 
One morning a few years ago I was surprised to 
