390 GEOLOGICAL SURVEY OF THE TERRITORIES. 



Eocky Mountains may be found in an article by the author in the Popular 

 Science Monthly for May, 187G. 



It gives me pleasure to acknowledge my indebtedness and tender my 

 thanks to Messrs. Thomas Bland and W. G. Binney, Dr. James Lewis 

 aiid Prof. Edward S. Morse, for much kind help and good counsel, both 

 before and after the completion of this manuscript. 



Class GASTEROPODA. 



Order PECTINIBRANCHIATA. 



Family VALVATID^. 

 Valvata sincera, Say. 



Lakes ; San Luis Valley 1 specimen. 



Reported also from Salt Lake {Hemphill). Inhabits the Western 

 States. 



My single shell was found dead upon the beach. It is typical, except 

 in size, which exceeds that of any other specimens 1 have seen. I agree 

 with Mr. W. G. Binney that I have never seen " specimens referred to 

 this species that can easily be distinguished from carinate forms of 

 Y. tricarinata." 



Valvata virens^ Tryon. — Coeur d'Alene Lake, Montana {Hemphill ) ; 

 Pacific coast. 



EISSOID^. 



AMNICOLIN^. 



Tryonia clatharata, Stm. — Colorado Desert {BlaJce). 

 Tryonia protea, Gld. — Colorado Desert {Blake.) 



Somatogyrus isogonus yae. subglobosus, Say. 



Lakes ; San Luis Valley 5 specimens. 



l^orth western part of the Union {Say). 



All my specimens were dead. My time was so limited at this inter- 

 esting point that I could not search the deep water for living moUusks. 



Amnicola turhinij'ormis, Tryon. — Crane Lake Valley and Surprise Val- 

 ley, Northeast California ( Gahh) ; near Fort Hall, Idaho {Beid) j Truck- 

 ee, Nevada {Carlton). California. 



Amnicola longinqiia, Gld. — Colorado Desert {Blalce). 



Fluminicola Nuttalliana, Stm. — Warm Springs, near Salt Lake, Utah 

 {Beid) ; Upper Des Chutes River, and Klamath River, Oregon {New- 

 berry). Oregon and California. 



Fluminicola semiualis, Stm. — Salt Lake, Utah {Beid) ; Oregon and 

 Washington Territory {Newberry). 



FlumirAcola Hindsii, Stm. — Salt Lake^ Utah {Beid) ; River Kootanie 

 and stream at foot of Rocky Mountains, 4,G2G feet, British Columbia 

 {Lord). 



