FAMILY LYMN^EID^E 77 



California ! Oregon ! Seattle, Wash. ! Sumas Lake, British Colum- 

 bia ; Vancouver Island ! headwaters of the Yukon ! Lake Marsh ! 

 Lake Lindeman ! Old Fort Yukon, Alaska ! Saccatalontan and Nu- 

 lato ! Lower Yukon, and in the Yukon delta ! Dall River ! north of the 

 Yukon in Alaska. Point Romanof , Norton Sound, Alaska ! Avacha 

 Bay, Kamchatka ! etc. 



This well known species is almost universally distributed in the 

 quiet waters of boreal America, and in the Pleistocene marls. The 

 distinctions which have been relied on to separate L. haydeni'Lea.) 

 and L. expansct Haldeman, are due to pathologic mutations. L. 

 nuttalliana and proximo. Lea, are trivial varieties. 



Lymnaea (Stagnicola) reflexa Say. 



Lymneus reflex us SAY, Journ. Acad. Nat. Sci. Phila., n, p. 167, 1821 ; Am. 



Conch., iv, pi. xxxi, fig. 2, 1832 (Lakes Erie and Superior). 

 Ltmneus elongatus SAY, Journ. Acad. Nat. Sci. Phila., n, 



p. 167, 1821 ; not of Draparnaud, 1805. 

 Ltmneus umbrosus SAY, Am. Conch., iv, pi. 31, fig. I, 



1832 (new name for elongatus Say). 

 Limncea exilis LEA, Trans. Am. Phil. Soc., v, p. 114, pi. 



xix, fig. 82, 1837 (pathologic mutation). 



Range. Northern United States and Canada. 

 Prairie Lake, near Red River of the North ; and 

 Beaver Creek, Manitoba. 



This species barely crosses the boundary and may 



f , 11 i j j FIG. 58. Lym- 



be one of those captured by the northward drainage ' 



J . ncea reflexa bay. 



when the headwaters of the Mississippi were inter- 

 rupted and turned northward by the changes in the land levels of this 

 region which have been elucidated by the late General G. K. 

 Warren. 



Lymnaea (Stagnicola) catascopium Say. 



Lymncea catascopium SAY, Nicholson's Encycl., Am. ed. , II (no pagination), 



pi. 2, fig 3, 1817 (Delaware River). 



Lymntzus catascopium SAY, Am. Conch., vi, pi. 55, fig. 2, 1832. 

 Lymnea cornea VALENCIENNES, in Humboldt and Bonpland, Rec. d'obs. de 



Zool., n, p. 251, 1832. 

 Limncea sumassi BAIRD, Proc. Zool. Soc. London, 1863, p. 68. BINNEY, 



Land and Fw. Sh. N. Am., n, p. 43, fig. 57 (not fig. 56), 1865 (British 



Columbia). 



Range. L. catascopium Northern United States to the Rocky 

 Mountains, Canada and northward ; var. sumassi: Idaho, Washing- 

 ton and British Columbia. 



Ottawa, Canada ! LTngava, Labrador ! Lake Winnipeg, Manitoba ! 

 Hudson Bay drainage of Keewatin ! Moose River at Moose Factory, 



