VOL. XIX, PP. 193-198 DECEMBER 31, 1906 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



WEST AMERICAN MITRID^E NORTH OF CAPE 

 ST. LUCAS, LOWER CALIFORNIA. 



BY MRS. M. BURTON WILLIAMSON. 



As the nomenclature of our West Coast Mitras appears to be 

 somewhat confusing, it has been thought advisable .to review 

 some of the literature upon this subject and also to give excerpts 

 from letters written upon the synonomy by well known authori 

 ties. As indicated by the title this paper does not include Gulf 

 species nor are fossil forms included unless represented by 

 recent shells. 



The writer desires to acknowledge her obligation to Dr. Wil 

 liam Healey Dall and Dr. Paul Bartsch, of the U. S. National 

 Museum, Prof. James Cosmo Melvill, of Shrewsbury, England, 

 Mr. Edgar A. Smith, British Museum, Sowerby and Fulton, 

 London, England, Dr. R. E. C. Stearns, Mr. Henry Hemphill 

 and Fred L. Button, Esq., of California, for courtesies received 

 from them. She is especially indebted to the British Concholo- 

 gists for original descriptions of Mitra idse, Melv., M. fultoni 

 E. A. S, and a very fine, typical example of M. one ntalis Gray 

 =M. maura Swains. 



FAMILY M1TRID/E. 



Mitra episcopal is Lam, the type of this Mitriform family, ranks high 

 among showy shells but the West Coast representatives are noted for their 

 somber aspect. 



Of the relationship of this family, Dr. William Healey Dall says: " While 

 I have no doubt in my own mind that Voluta, Scaphella, Turbinella, Fas- 

 ciolaria, Mitra and the Fusidse all proceeded from one stock and could 

 not be separated as families in the Eocene time, yet that does not exclude 

 the recognition of the divergencies which have been brought about at the 

 present epoch, by gradual evolution from more compact original groups.* 

 * Trans. Wagner Free Ins. Sci., Phila., Vol. Ill, 1820, p. 92. 

 35-PKor. BIOI, Soc. WASH,. Vol.. XIX, 1906. 



