ixGEKsoLL.] ZOOLOGY PHYSID^. 401 



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, abundant springs near 

 Saguache, where there wa^ seemingly nothing whatever to stunt their 

 growth. 



Physa Woliiana, Lea. 



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

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

 rado," collected by Prof. J. W. Powell, which he named PhysaWolfiana. 

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

 locality {vide Observations, XIII, 67; PI. xxi, 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 Lordi, Baird. — British Columbia (Lord), replacing P. Jietero- 

 siropka on the higher ground toward the Eocky Mountains ; east of Fort 

 Colville, Washington Territory {Nortliivestern Boundary Survey). It is 

 not unlikely that P. ClarJcei and the two following species will prove 

 identical with this, differing only in size and color. Here, as in Limnea, 

 the shell is subject to such variation that it is precarious to predicate 

 specific rank upon the shell alone, particularly it the specimens be few 

 and localities isolated. 



Physa ampullacea, Gonld. — Oregon and Washington Territory {Cooper)\ 

 Ehett's Lake, Calilornia, and Upper Klamath Lake, Oregon [Newherry). 



Physa ancillaria, Say. — liuby Valley, Nevada {Simpson). 



Physa gyrina,S-dy. — Carson, ISeyada, {Wheatley); Nevada {Simpson). 

 Missouri Eiver. 



Physa humerosa, Gould. — Colorado Desert, Pecos Eiver {BlaJce). 



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



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



Physa Haicnii, Lea. — White Pine, Nevada {Remphiii). 



Physa Saffordii^ Lea. — Fort Hall, Idaho, and Snake Eiver Valley, 

 Utah {Reid); Nevada and Eastern Idaho {Hemphill). 



Physa virgata. — Gila Eiver {Gould). Southern California. 



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

 Creek, southwest Idaho {Gabb). 



Physaoccidentalis, Tvjou. — For t Colville, Washington Territory (Sbrw) ; 

 Warners Valley, Oregon {Gabb) ; Truckee,. Nevada {Carlton). 



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



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

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



Pkysa Nuttallii, Lea. — Lewis Eiver, Idaho {Nuttall). 



Physa Cooperi, Teton. 



Between the Animas and La Plata 5 specimens. 



Also recorded from a spring in Crane Lake Valley, northeast Cal- 

 ifornia {Gabb). I do not feel quite sure of this determination-, because 

 of the immaturity of the specimens, and the fact that I do not have 

 access to types ; nor do I altogether trust in the validity of the species. 



Bxdimis hypnomm, Linn^us. 



Camp 9-10 : Grand Eiver Valley 50 specimens. 



Bear Eiver {Barber) 5 specimens. 



26 H 



