26 



LAND AND FRESH WATER MOLLUSKS 



Astoria, Oregon ! Victoria, Vancouver Island ; Chilli wak Lake, 

 British Columbia. 



A variety megasoma, more than four times the size of the typical 

 germana, but otherwise quite similar, is occasionally found ; some 

 from northern California (Stearns) are in the National Museum. 



Polygyra monodon Rackett. 



Helix monodon RACKETT, Trans. Linnean Soc., xm, p. 42, pi. v, fig. 2, 1822. 

 MORSE, Am. Nat, i, p. 151, figs. 12, 13, 1867. 

 BINNEY, Land and Fw. Sh. N. Am., I, p. 120, figs. 200- 

 205, 1869. 



Range. Eastern United States, east of the plains 

 region, from Texas to Minnesota and northward. 

 Moose Factory, James Bay ! 



FIG. 3. Poly- 

 gyra monodon 

 Rackett. 



Polygyra albolabris Say. 



Helix albolabris SAY, Nicholson's Encycl., ist Am. ed., pi. I, fig. I, 1817 ; Am. 

 Conch., II, pi. xn, 1831. MORSE, Am. Nat., i, p. 6, pi. i, figs, i-u, 

 1867. BINNEY, Land and Fw. Sh. N. Am., I, p. 136, figs. 229-232, 

 1869. 



Range. Eastern United States, from Georgia and Arkansas north- 

 ward to the Saskatchewan. 



FIGS. 4-6. Polygyra albolabris Say, \. 



Lake Superior region ; Lake Winnipeg, Manitoba ; and northward 

 to the Saskatchewan River (Richardson). 



