DIMYAEIA-UNIONIDAE ANODONTA OREGONENSIS. 



051 



Dr. Prime states, in his " Monograph" loc. cit., that this species is dis- 

 tributed over such a vast area of country, and varies so much according to 

 the different localities in which it is found, that it is hardly surprising that 

 its numerous varieties should have been mistaken for so many species. It 

 was secured in but one locality inMiddle Utah, viz, on mountain sides 

 near the Beaver River. 



PISIDIUM VARIABILE, Prime. 



Cydas nitida, MIGHELS, LINSLEY, Am. Jour., xlviii, 1845, 276. 

 Pisidium variabile, PRIME, Proc. Bost. Soc. Nat. Hist., iv, 1851, 163. 

 Pisidium grande, WHITTEMORE, in litt., 1855. 

 Musculium variabile, ADAMS, Rec. Gen., ii, 1858, 452. 

 Pisum variabile, ADAMS, loc. sub cit., ii, 1858, 660. 



Pisidium variabile, PRIME, Mon. Am. Corbiculadae, Smithson, Miscel. Pub., No. 145, 

 1865. 66. 



According to Prime, this species is distributed throughout North 

 America, in New England, the States of New York, Pennsylvania, and 

 Virginia. 



Specimens were found to be abundant in Colorado, near the Rio 

 Grande River. 



FAM. UNIONIDAE 



A number of Anodonta were collected during the field season of 1872, 

 but, unfortunately, were destroyed or lost in transit to Washington, with 

 the exception of the following species : 



ANODONTA OREGONENSIS, Lea. 



Collected from the Sevier River, Utah, by Lieut. Wallace Mott, U. S. 

 A., and Dr. H. C. Yarrow. 



