DESCRIPTIONS OF NEW SPECIES OF MOLLUSKS OF THE 

 FAMILY TURRITIDAE FROM THE WEST COAST OF 

 AMERICA AND ADJACENT REGIONS. 



By William Healey Dall, 



Honorary Curator of Mollusks, United States National Museum. 



INTRODUCTION. 



In the course of my revision of the marine mollusk-f auna of West- 

 ern America it became necessary to take up the present family, which 

 was in a regretable state of confusion. This involved a review of the 

 generic nomenclature as well, since it was well known that many in- 

 valid names were currently used, following the early work of Doctor 

 Carpenter and others. 



Circumstances connected with the war made a general revision of 

 the nomenclature of the family impracticable. A revision of the 

 genera chiefly concerned with the West American species and a bib- 

 liography of names which had been used for groups connected with 

 the family was, however, possible and has already been issued.^ 



The present paper is to be construed in the light of the data pre- 

 sented in the above-mentioned publication. In reviewing the fauna 

 from San Diego northward it became necessary to include to a great 

 extent that of the regions south of the United States boundary, since 

 experience had shown, in connection with a study of the bivalves, 

 that a certain proportion of the species extended their range not only 

 into the Panamic fauna but even as far south as Peru. 



In going over the material in the collection of the United States 

 National Museum a large number of new forms were discovered, and 

 their description forms the subject of this paper. A few of the 

 species of Doctor Carpenter are now figured for the first time from 

 his types. In all somewhat over 200 species are considered, of which 

 181 are new. Of these 93 belong to the fauna of the western coast 

 of the United States from the Arctic Ocean to San Diego, California, 

 including one species from our Hawaiian territory. Eleven species 

 belong to the west coast of South America and its faunal connection, 

 the Galapagos Islands ; 89 belong to the Panamic fauna and its north- 

 ern extension into the Gulf of California and the shores of the Cali- 

 fornian peninsula. 



iProc. U. S. Nat. Mus., vol. 54, No. 2238, pp. 313-333, Apr. 5, 1918. 



Proceedings U. S. National Museum. Vol. 56— No, 2288. 

 115690— 19— Proc.N.M.vol.56 1 1 



