AIR-BREATHING SNAILS AND SLUGS 



287 



Fig. 275 



The suture is deep, also the umbilicus, while the lip 

 is unusually thick for the size of the shell. 



Glyptostoma ncvsherryanuni^ V\ . 

 G. Binney, Newberry's Snail, is a 

 yery distinct species, tound in 

 southern California, particularly 

 around San Diego. A basal yiew 

 of a small specimen is shown in 

 Figure 275, but large ones grow 

 to a diameter of an inch and a half. The spire is 

 flattened, and the umbilicus is yery large, distinctly 

 showing the coil ot rounded whorls. The lip of the 

 aperture is thin and acute, the whorls are six in num- 

 ber, and the color ot the shell is dark brown, some- 

 times almost black. It is quite distinct from any 

 other shell. 



P o I y (/ y r a tovsnsendiana^ 

 Lea, Townsend's Snail. This 

 distinct species, whose line 

 large shell is shown in Figure 

 276, is a true northerner, be- 

 ing found mostly in Oregon, 

 Washington, and even much 

 farther to the north. The shell is strong, the spire 

 but little elevated, the color yellowish or brownish, 

 sometimes mottled. Peristome like a white horse- 

 shoe, umbilicus large and distinct. The surface is 

 marked with many microscopic spiral lines, which 

 are crossed b}^ roughened ridges. Var. ptychophora^ 

 A. D. Brown, is found in Idaho and eastern Oregon. 

 The shell is nearly smooth and is of a light horn- 

 color, but it has the regular markings, and the broad, 



Fig. 276 



