104 



THE NAUTILUS, 



IX. Black River, Catahoula Parish, Louisiana. 

 Lampsilis fallaciosus {Sm.') Quadrula heros domheyana Val. 



Simps. " trapezoides Lea. 



Ohliquaria reflexa Raf. 



VALVATIDAE OF THE WESTERN NORTH AMERICA. 



BY HAROLD HANNIBAL. 



While preparing a paper on the tertiary fresh-water fossils of 

 Western North America it became necessary to go over the litera- 

 ture and examine all the Valvatidae available. This included speci- 

 mens from the type localities of V. utahensis and V- virens and part 

 of the original lot from which V. humerah's californica was described. 

 There is therefore no doubt as to the authenticity of the determinations. 



Two new fossil species have turned up in the Upper Lahontan 

 (Quartenary) of Nevada and Southern Oregon, descriptions of 

 which are given here. In a paper on fresh-water fossils now in 

 progress, all the species will be figured together for comparison. 



On account of the complex and unsatisfactory nature of a key the 

 following table has been devised : 



