SCIENTIF^IC RESULTS OF EXPLORATIONS BY THE U. 3. FISH 

 COMMISSION STEAMER ALBATROSS. 



[Published by permission of Hon. Mar.4l]all McDonald, Coinmissioner of Fisheries.] 



No. XX.— ON SOME NEW OR irrERESTING WEST AMERICAN SHELLS 

 OBTAINED FROM THE DREDGINUS OF THE U. S. FISH COMMISSION 

 STEAMER ALBATROSS IN 1888, AND FROM OTHER SOURCES. 



BY 



Wm. H. Dall, 



Curator Department of Molliisks, U. S. National Museum. 



(With Plates v-vii.) 



Among tlie dredgings of the Albatross and other West American 

 shells received during the last few years several forms of unusual interest 

 have turned up, and it was thought desirable to have them described 

 and illustrated for the use of students and collectors of the mollusks of 

 this fauna. Some old species which have never been figured, or have 

 been im[>erfectl3' figured, are here illustrated. 



The confusion which has attended the history of some of them has 

 been more or less successfully cleared up and distinctive features 

 pointed out. In the absence of a comi)lete monograph of West American 

 species, less ])retentious contributions to the knowledge of the fauna 

 will help students to abetter understanding of it, and thus advance the 

 science and the i)rospect of a more comprehensive work. I have been 

 much indebted to the kind cooperation of Mr. J. J. Rivers, of the Uni- 

 versity of California, Miss Ida M. Shepard, of Long Beach, and Mrs. 

 M. Burton Williamson, of University, California, as well as several 

 other ladies mentioned in the text. 



Geuus EUPLEURA Adams. 



The species of this genus have been in a good deal of confusion, which 

 I have endeavored to clear up in my contributions to the Tertiary 

 Fauna of Florida (Transactions of the Wagner Free Institute of Sciv 

 ence, Philadelphia, vol. iii, p. 141. 1800). Numerous specimens of the' 

 Pacific form were dredged by the Albatross off the coast of Lower Cal^ 

 ifornia near Cerros Island. I have thought it desirable to figure the 

 various forms Jirom typical examples in order to clear up the confusion. 



Proceedings National Museiuu, Vol. XIV— No. 849.. 



173, 



