360 THE CHICAGO ACADEMY OF SCIENCES. 
a trifle inflated, about two-fifths the length of the shell; peristome thin, 
sharp, with a slight internal rib, chestnut colored on the edge; inner 
lip narrow, reflected and appressed to the columellar region leaving a 
very narrow chink; the parietal callus is thin and narrow; a distinct, 
sharp but not heavy plait extends across the columella in an upward 
direction ; the axis is slightly twisted. 
Length. Width. Aperture length. Width. 
21.00 8.50 8.50 4.00 mill. Type, proxima. 
24.00 10.00 11.00 5:50 | San Francisco Cale 
27.50 11.50 12.00 6.50 “ San Mateo, Cal. 
28.00 12.00 13.00 7.00 “ # ‘i 
18.00 8.00 7.50 4.00 “ Wyoming. 
Types: Proxima, Lea, two specimens, Smithsonian Institution, 
No. 29082; cotypes, Philadelphia Academy of Sciences, No. 58503; 
californica, Sowerby and interstriata, Sowb., British Museum of Natu- 
ral History, London, England. 
Type Locatity: Proxima, Arroya, San Antonio, Cal. ; californica, 
California ; interstriata, California. 
ANIMAL, JAW, RaApDULA and GENITALIA: Not examined. 
RANGE: (Figure 42) California to Wyoming; Washington south 
to Southern California. The regional map shows that pro.sima is 
common to the Columbian, Coloradoan, Great Basin and Californian 
regions. It is also characteristic of two great river systems, the Co- 
lumbia and the Colorado. The records show that proxima has a wide 
range in Western America from the 35th to the 48th degree of North 
latitude. It seems to thrive from near the sea level to a height of over 
7,000 feet. 
RECORDS. 
CALIFORNIA: Mountain stream near San Francisco, San Francisco Co. 
(Button; Cooper; Nason; Rowell; Stearns; Walker); San Mateo Co. (Hemp- 
hill) ; South Fork Pitt River, Modoc Co. (McGregor); Arroya, San Antonio, 
San Bernardino Co. (Lea; Trask). 
OreEcon: Dallas, Polk Co. (Dall; Stearns); southeast Oregon (Gabb) ; 
Steins Valley, Harney Co. (Tryon). 
UtTaH: Near Salt Lake City, Salt Lake Co. (Hemphill); near Logan, 
Cache Co. (Hemphill; Keep; Walker); Beaver City, Beaver Co., high up in 
Wasatch Mountains (Palmer); Bear Lake, Rich Co. (Walker). 
WASHINGTON: Spokane, Spokane Co. (Smith. Inst.) ; Columbia River 
(T. B. Wilson). 
Wyominc: Alkali Springs, forty miles north of Almond, Sweetwater Co. 
(W. C. Knight). 
GEOLOGICAL DiIstTRIBUTION: Unknown. 
EcoLocy: In mountain streams or small lakes, generally at high 
altitudes. 
