140 WEST AMERICAN SHELLS 
teeth; diameter 18mm.; from Arizona and New 
Mexico. 
Polygyrame- 
arnsu, Dall, 
Mearns’s 
Sembee eas ns 
shown in Fig- 
ure 116. This 
shell is of a Fig. 116,x 3 (*) 
pinkish brown color. The details of the shell are 
well brought out in the three figures. Diameter, 
13mm. Found in Arizona and in Hachita Grand 
Mountain, New Mexico. 
Valloma pulchélla, Miull., the Beautiful Vallonia, 
is a little mollusk whose shell consists of four 
rounded whorls arranged in a_ flattened spiral 
form. ‘The umbilicus is large and open, the aper- 
ture nearly circular, the peristome white, reflected, 
and forming a nearly complete circle. The shell is 
whitish, thin, and in our variety is usually 
marked by cross-ribs. Its diameter is barely an 
eighth of an inch. The species is very widely dis- 
tributed. A few years ago it suddenly appeared in 
Los Angeles, in the yard of Dr. Stearns. It is also 
reported from Oakland and many other localities 
in California, also from Utah and adjacent States. 
Vallonia costata, Mull, the Ribbed Vallonia, is 
another very small species, the shell being only 
2.5mm. in diameter. Horn-colored, nearly flat, 
umbilicated, with regularly set membranous ribs, 
and fine strie between them. It has about the same 
range as the last species. 
