Fossil Freshwater Mollusks from Oregon 



GENUS : VIVIPARUS MONTFOBT 



VIVIPABUS, SP. 



One lot of material from University of Oregon locality 211, 

 said to have come from between Crooked River and Harney Lake, 

 Oregon, consists entirely of compressed shells, thoroughly cemented 

 and crystallized. All are so badly distorted that specific identifica- 

 tion is impossible but conspicuous in the mass is a robust Viviparus 

 similar to some of the species, leai for instance, from the Laramie 

 and Eocene strata of the Rocky Mountains. It is possibly the same 

 as V. washingtonianus Hannibal, 7 but does not appear to be sub- 

 carinate on the periphery. The last was described from the 

 "Tejon" Eocene strata of Little Falls, Washington. The Oregon 

 shells appear more like V. turneri Hannibal 8 described from Eocene 

 strata, Truckee Lake beds, Nevada. Since no member of the family 

 Viviparidae is known to have persisted west of the Rocky Moun- 

 tains after the Eocene, it seems safe to refer the material from 

 locality 211 to that age. 



GENUS: PISIDIUM PFEIFFER 

 PISIDIUM, SP. 



The collection of shells from University of Oregon locality 212, 

 Warner Lake beds of eastern Oregon, contains numerous specimens 

 of Pisidium. There appear to be two species represented, a smooth 

 one and a rugose one, but the nomenclature in this genus is so tre- 

 mendously confused that identification is exceedingly difficult, 

 well nigh impossible with certainty. 



LIST OF LOCALITIES 



University of Oregon locality numbers 200, 201, 202, 203, 204, Snake 

 River Valley, Oregon. Pliocene. Contains Valvata oregonensis, Parapholyx 

 packardi, Pisidium sp., and a huge species of costate Vorticifex. Preservation 

 is so poor that specific identification is not possible with certainty, the shells 

 being usually represented by casts, or impressions. The Vorticifex is unde- 

 scribed and represented by fragments at several localities. 



205. Central Oregon. Pliocene. Contains Valvata oregonensis, Parapholyx 

 packardi and a species of Pisidium firmly cemented together. The shells are 

 not easily extracted. 



206. No locality. Contains poorly preserved Valvata oregonensis, Para- 

 pholyx packardi and the costate Vorticifex. 



207. Snake River Valley, Oregon. Pliocene. Vorticifex condoni abun- 

 dant; Pisidium, two species abundant; Parapholyx packardi and Valvata ore- 



* Hannibal, H. Proc. Mai. Soc., London, Vol. 10, p. 194, pi. 8, fig. 32, 1912. 

 8 Opt. Cit., p. 194, pi. 8, fig. 31. 



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