AIR-BREATHERS 145 
the shell to its very apex. The spire is small and 
consists of three delicate whorls. The length of 
the whole shell is three-fourths of an inch. The 
specimen from which the drawing was made was 
collected near Salt Lake, Utah. 
Succinea avara, Say, the Greedy Amber- 
snail, Figure 124, has a smaller shell than a 
the last species. The form of its delicate, ‘€& 
horn-colored shell is shown in the figure, 
which is rather larger than the real shell. 
This species is reported from Idaho and southern 
California. Several varieties of this species live 
on the Santa Barbara Islands. 
Succinea rustica, Gld., the Rustie Amber-snail, 
is found in Oregon, California and Nevada. The 
shell is thin and fragile, of a pale greenish horn- 
color, surface rough and without luster, spire 
acute, length one-half an inch. 
Succinea sillimani, Bland, Silliman’s Amber- 
snail. Shell oblong-ovate, thin, striate, shining; 
spire short, aperture large, oblique; length 20 mm. ; 
found in California and Nevada. 
Succinea oregonénsis, Lea, the Oregon Amber- 
snail. Shell one-fourth of an inch long, though 
sometimes longer, thin, yellow, rather coarsely 
striated, aperture two-thirds the length of the shell. 
Onchidélla carpentéri, W. G. Binney, Carpen- 
ter’s Onchidella. This is a little creature shaped 
like a short, fat Limax, the ends rounded, and the 
upper surface arched. The coriaceous mantle 
overhangs the locomotive disk. The body is smoke- 
colored; length, 5mm. It lives near the water, 
and is found from the Straits of Fuca to Mexico. 
Fig. 124 
