196 Williamson West American Mitridtz. 



fered in toto from what he had " always called M. orientalis Gray,=J!f. 

 maura Swains, from Peru and Chilian Coasts." That species called M.. 

 chilensis by L. C. Kiener is admirably figured under the latter name by 

 Kiener Coq. Viv., Mitra, tab. 10, figs. 28, 28a. That shell is larger and 

 broader than the Californian shell, smoother and more shining the spiral 

 pitting microscopical, the shape of the mouth distinct, more effuse, outer 

 lip and the whorl pinched in towards the center as in the Californian 

 species plicae of columella slightly more oblique."* Upon further com 

 parison between M. orientalis (M. maura}, and M. idse, Professor M el vill says 

 of the first named, that it corresponds " exactly with the plate in Sowerby's 

 Thesaurus Conchyliorum III, PI. 354 (Mitra) t. 40, being a more incrassate, 

 uncouth shell than idee and apparently smooth, uniformly black ; with a 

 lens, slight pitting is discernable. The form of the mouth is also quite 

 different from idie"^ He adds that English Conchologists " such as Mr. 

 G. B. Sowerby, Mr. Edgar A. Smith, Mr. Sykes, and Mr. Fulton all recog 

 nize the specific differences between idse and inaura (orientalis)" Dr. 

 Win. H. Dall and Dr. Paul Bartsch also agree that, " The California species 

 is distinct and should retain the name M. idse Melv." J 



The fine example (Fig. 7) of Mitra from Peru, received, through the 

 courtesy of Professor Mel vill, from Sowerby and Fulton, bears this label : 

 " Mitra orientalis Gray 1834 

 inaura Swainson, 1835 

 chilensis Reiner, 1839." 



The whole question evidently resolves itself into this : Swainson's Mitra 

 maura has not been found upon the Californian Coast, and, Swainson's 

 Mitra maura, on account of priority, is now called M. orientalis.^ M. orient 

 alis is not found north of Cape St. Lucas, Lower California, and the geo 

 graphical listing of this species is incorrect. While P. P. Carpenter lists 

 M. maura among the Upper California Fauna in his Report on Moll, of W. 

 Coast of N. Amer. in 1856,|| in the British Rep't for 1863, he has this note: 

 ' Mitra maura Swains. Nutt. = orientalis Gray = chilensis Gray, Kien. Very 

 dark and plain. Peru. Sand between rock 1. w. Cuming," in Carpen 

 ter's Catalogue of Mazatlan Shells (1857) there is no mention of M. orientalis 

 (maura) in place there are Mitra lens Mawe, and Stngatella tristis Brod. Dr. 

 R. E. C. Stearns also lists M. lens said M. tristis among other Mitras but does 

 not include M. orientalis among the "Shells of the Tres Marias" (Proc. U. 

 S. Nat. Mus., Vol. XVII, pp. 139-204). 



Of Mitra idse in regard to relationship with other black Mitras from West 

 Coast of U. S. A. and South America, Professor Melvill says : "lens, maura 

 (orientalis), caliginosa, fultoni, idse and others may have been derived from 

 a common ancestor." 



* Letter. 



t Letter. 



I Letter. 



\ Of the name orientalis for this shell, Professor Melvill writes: " It is an unfortun 

 ate name, certainly, being a shell of the Western, not the Eastern hemisphere and is 

 exactly in the same position, therefore, as Cyprse ( Trivia) madagascariensis, which , as every 

 body knows, does not occur anywhere near Madagascar." 



|| Binney's Bibliography of N. Amer. Conchology, Vol. I, p. 300. 



