LYMN^EID^ OF NORTH AMERICA. 441 



Limncea ampla? Tryon, Con. Hald. Mon., p. 91, pi. 16, fig. 10, 1872 (non 

 Mighels).— Cat. Coll. Nat. Hist. Bth. Prov. Mus. Victoria, p. 95, 1898. 

 Limncea randolphif Dall, Alaska Moll, p. 71, 1905. 

 Shell: Elongate-globose, inflated, generally rather solid; perios- 

 tracum pale horn, darker in some specimens ; surface shining, lines of 

 growth coarse and close-set ; spiral striation pronounced ; apex wine 

 colored ; whorls 4*/2 to 5, rapidly increasing in size, inflated, tumid ; 

 spire short, broadly conic; nuclear whorls lyi in number, flattened, 

 especially the first whorl which is very flat, sunken in the volution of 

 the second whorl, and separated by a deep sutural channel (pi. XLIX, 

 fig. P) ; sutures impressed; aperture ovate or elliptical, occupying more 

 than half the length of the shell; outer lip convex, thickened within by 

 a varix edged with brown; inner lip somewhat erect, reflected over 

 the parietal wall to form a thick callus and raised above the umbilicus 

 forming a broad, flat projection partly hiding the umbilical chink; axis 

 not much twisted, but the columella is slightly thickened and in some 

 specimens the inner lip is appressed to such an extent as to form a 

 rather well-marked plait; the umbilical chink varies from a small slit 

 to a rather wide opening. The surface is sometimes malleated. 

 Length. Breadth. Aperture length. Breadth. 



19.00 12.00 12.25 6.25 mill. Tryon's type. 



18.25 11.50 11.50 5.50 " 



20.50 12.20 12.60 7.00 " Lake Superior. 



28.00 18.00 17.50 10.10 " 



22.50 12.75 13.50 7.50 " 



19.50 13.25 12.50 8.10 " 



19.75 11.50 10.50 7.50 " 



16.00 9.30 9.80 5.50 " 



17.00 10.00 10.00 5.50 " 



22.75 13.00 13.00 7.50 " 



29.00 19.50 19.50 11.50 " Rainy Lake. 



25.00 16.50 19.50 11.50 " 



Types: Two specimens, ex Gabb., Acad. Nat. Sci., Phil., No. 

 58506. 



Type Locality : Hell Gate River, Montana. 



Animal, Jaw, Radula and Genitalia: Not examined. 



Range: (Figure 49). Western Ontario north of Lake Superior 

 (86°) west to Washington, Alberta south to southern Idaho. Binneyi 

 is a species of the Boreal (Canadian) and Transition life zones. It 

 occupies both the Great Lakes drainage and that of the streams empty- 

 ing into the Columbia River (Columbian and Canadian regions). There 

 seems to be no question concerning the identity of the shells occupying 

 these very diverse drainage areas. Specimens from Montana and 

 Yellowstone Park indicate that the species occupies the upper drain- 



