AIR-BREATHING SNAILS AND SLUGS 293 



chiefly in forests, concealing itself under 

 leaves and the bark of dead trees. It is about 

 the size and shape of a grain of wheat, thin, 

 dark horn-colored, very bright and glistening. 

 This species lives in Europe, where it is 

 known in France as "la brillante," also in the East- 

 ern states, Alaska, Oregon, and Utah, and it has 

 even been collected on Grizzly Peak, back of the 

 University of California. 



The members of the old genus Pupa are 

 4-^ mostly very small, though some of them grow 

 to a fairly good size. The shell shown in 

 Fig. 284 pjorure 284 is a representative of this great 

 division of land shells. The picture is small enough, 

 but even the little cross beside it is too large for 

 truth. The name is Vertigo calif ornica. Rowel 1, the 

 California Pupa. The shell is brown, and on the 

 sides of the aperture are four tiny white teeth. It 

 lives in various parts of California on the mainland, 

 and two varieties live on Catalina Island. 



The Pupas belong to a very ancient family, as we 

 know from the fact that a little fossil shell belong- 

 ing to this genus was found in a coal mine in Nova 

 Scotia, and is reckoned as the oldest land shell ever 

 discovered. They take their name apparently from 

 their resemblance to the cocoon of an insect, which 

 in turn is supposed to resemble a doll. Many of 

 these shells are exceedingly minute, measuring less 

 than two millimeters in length. They are usually 

 found in lowly positions, such as among grass roots, 

 under old cacti, in river drift and similar positions. 



