152 i 111. CHICAGO ACADEMY OF SCIENCES. 



Lymnaea stagnalis wasatchensis (Hemphill). Ms. Plate XX, 

 figures 10-12. 



Shell : Much elongated, narrow, thin ; color light yellowish horn ; 

 surface with the characteristic sculpture of stagnalis; whorls G l / 2 flatly 

 rounded, increasing slowly in size; last whorl small, generally not in- 

 flated, but well rounded; spire very long, acutely pointed, occupying 

 more than half the length of the shell; sutures well marked, aperture 

 small, roundly ovate; inner lip appressed tightly to the parietal wall 

 and to the columellar region; there is no umbilical chink; axis with 

 a strong plait as in stagnalis appressa. 



Length. Breadth. Aperture length. Breadth. 



42.00 17.00 19.00 12.00 mill. 



38.00 16.00 17.50 11.00 " 



32.50 14.00 15.00 9.50 " 



37.00 18.00 19.00 12.00 " 



45.00 20.00 22.00 13.00 " 



Type : Coll. Henry Hemphill. 



Type locality : Near Salt Lake, Utah. 



Animal, Jaw, Radula and Genitalia : Unknown. 



Range: (Figure 11) Western and Northwestern America. 



RECORDS. 



The records give a peculiar distribution for this species, showing 

 an area of about 1500 miles between the most northern record and 

 that from Alberta. The northern record seems authentic, the speci- 

 mens agreeing well with zvasatchensis. The race probably inhabits 

 most of the region north of the 40th parallel and west of the 110th 

 meridian. 



UNITED STATES. 



Utah: Near Salt Lake; near Logan, Cache Co. (Hemphill); Pangeritch 

 Lake, 25 miles north of Salt Lake, Tooele Co. (Wheeler expedition, Phil Acad.). 



Washington: Near Spokane Falls, Spokane Co. (Button); East of Col- 

 ville (Smithsonian coll.). 



BRITISH AMERICA. 



Alberta: Devil's Lake, near Banff (Woodruff). 



Mackenzie: Near Fort Anderson, N. lat. 68° (McFarland). 



Geological Range : Unknown. 



Ecology : No records have been seen detailing the habitat rela- 

 tions of this race. 



Remarks : Wasatchensis appears to be a strongly marked race of 

 stagnalis. Its chief characteristics are its long tapering spire, its 

 roundly ovate aperture and the general rotundity of the last whorl. 

 It may be at once distinguished from appressa by its more rounded 

 aperture and last whorl, appressa having more flat sided whorls. This 



