135 



Hot Springs, in a little lagoon filled at high water, large, clear, ampul- 

 lacea-\\\i.Q shells were conamon. In the few yards of exposed outlet of the 

 springs of hot sulphur-water from which the locality derives its name 

 and celebrity, there occurred in the greatest profusion a blackish glo bose 

 variety about one-fifth of an inch long. The temperature of this water 

 was at some jjoints as high ag 100^ F. In the basin of a still hotter 

 spring close by, whose waters were saturated with chlorides of sodium 

 and magnesium, hundreds of still smaller Physce (see below) were floating 

 about in mats, glued together by a tangle of confervoid vegetation and 

 the depositions of the water. All of these seemed to have lost the apex 

 of the spire by erosion, " which is extremely liable to happen to shells 

 living in water charged with alkaline salts other than lime." Yet 

 quite as small and black were the examples from the cold, clear, abun- 

 dant springs near Saguache, where there was seemingly nothing what- 

 ever to stunt their growth. 



Physa Wolfiana, Lea. 



In the Proceedings of the Philadelphia Academy for 1869, Mr. Isaac 

 Lea described a species of Physa from " the Hot Sulphur Springs, Colo- 

 rado," collected by Prof. J. VV. Powell, which he named Physa Wolfiana, 

 Inasmuch as my shells came from the exact and very limited station 

 and locality [vide Observations, XIIT, 67 ; PI. xxr, fig. 20) as his types, 

 I suppose I must have it; but as I cannot separate to my satisfaction 

 those which resemble that shell as described and figured from those 

 which do not resemble it, I have remanded all to the foregoing species. 



Physa Lordly Baird. — British Columbia {Lord), replacing P. lieiero- 

 stropha on the higher ground toward the Rocky Mountains ; east of Fort 

 Colville, Washington Territory {Northwestern Boundary Survey). 



Eemarks. — It is not unlikely that P. Clarkei and the two following 

 species will prove identical wilh this, differing only in size and color. 

 Here, as in Limnea, the shell is subject to such variation that it is pre- 

 carious to predicate specific rank upon the shell alone, particularly- if the 

 specimens be few and localities isolated. 



Physa ampullaeea, Gonld. — Oregon and Washington Territory {Cooper) ; 

 Ehett'sLake, California, and Upper Klamath Lake, Oregon (Neivherry). 



Physa ancillaria, Say. — 'Ra.by Valley, Utah {Swqjson). 



Physa gyrina, Say. — Carson, JS'evada ( Wheatley) ; Utah {Simpson). 



Physa humerosa, Gould. — Colorado Desert, Pecos River {Blake). 



Physa Grosvenorii, Lea. — Dayton, Nevada ( Wheatley). 



Physa parva, Lea. — Little Yalley, Nevada ( Wheatley). 



Physa Haivnii, Lea. — White Pine, Nevada {Remphill). 



Physa Saffordii, Lea. — Fort Hall, Idaho, and Snake River Valley, Utah 

 {Reid) ', Nevada and Eastern Idaho {Remphill). 



Physa virgata. — Gila River {Gould). 



Physa propinqua, Tryon. — White Pine, Nevada {Hemphill); Jordan 

 Creek, Southwest Idaho {Gabb). 



Physa occidentalis, Tryon. — Fort Colville, Washington Territory 

 {Rom) ; Warner's Valley, Oregon {Gahb) ; Truckee, Nevada {Carlton). 



Physa Blandii, Tryon. — Truckee, Nevada {Carlton). 



Physa malleata, Tryon. — Hell-Gate River, Montana, and Fandango 

 Valley, a part of Goose Lake Valley, Oregon {Gabb). 



Physa Nuttallii, Lea. — Lewis Eiv^er, Idaho {Nuttall). 



