AIR-BREATHING SNAILS AND SLUGS 295 



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 287, has a smaller shell than 

 the last species. It is delicate and horn- 

 colored, and the figure 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 Rustic 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 half an inch. 



Succinea oregonensis^ Lea, the Oregon Amber- 

 snail. Shell one-fourth of an inch in length, though 

 sometimes longer, thin, yellow, rather coarsely stri- 

 ated, with an aperture two-thirds the length of the 

 shell. 



Onchidella carpenteri, W. G. Binney, Carpenter's 

 Onchidella. This is a little creature shaped like a 

 short, fat Limax, with the ends rounded and the 

 upper surface arched. The coriaceous mantle over- 

 hangs the locomotive disk. The body is smoke- 

 colored, and its length is one-hfth of an inch. It 

 lives near the water, and is found from the Straits 

 of Fuca to Mexico. 



OncliidcUa boreal is, Dall, the Northern Onchi- 

 della, is but little larger than the last species. The 

 surface of the creature is black, with dots and 



