Stearns Fresh Water Mussel Shells. 69 



The late Dr. Cooper* regarded the West Coast mussels, Ano- 

 donta u'ahlamctensis, A. oregonensis and A. californiensis as va 

 rieties of A. nuttalliana, the last named being the first in order of 

 description and publication by Dr. Lea in his Observations, etc., 

 thus endorsing my conclusions as previously published in 1882. t 

 Whether Dr. Lea's species and Dr. Trask's A. triangularis and 

 A. rotundata are simply mutations of nuttalliana or otherwise, 

 it is not necessary to discuss at the present moment. These 

 and numerous undescribed mutations occur in a multitude of 

 localities, often in great abundance, in the above-named West 

 ern basins and their tributaries, alike in running or still waters, 

 subject to various environmental conditions. 



* Catalogue of West American and many Foreign Shells, etc., printed for the State 

 Mining Bureau, April, 1894, Sacramento, State Printing Office, 1894. 



T On the History and Distribution of the Fresh Water Mussels, and the Identity of 

 Certain Alleged Species. Proc. California Academy of Sciences, November 20, 1882. 



