THREE NEW LAND SHELLS OF THE GENUS OREOHELIX 



FROM ARIZONA 



By William B. Marshall 



Assistant Curator, Division of Mollusks, United States National Museum 



The study of a collection of Oreohelix made by Mrs. Mary Vaux 

 Walcott in the canyon at Supai, Coconino County, Ariz., in 1928, 

 and presented by her to the United States National Museum, not 

 only proved that they belonged to a new subspecies, but their exam- 

 ination entailed a close scrutiny of forms long since contained in our 

 collection but not previously adequately studied. Among these is a 

 new species collected by Dr. Walter Hough in Navajo County, Ariz., 

 and a subspecies of this collected by Dr. E. A. Mearns on Clear 

 Creek, near Winslow, Navajo County, Ariz. All of these are described 

 below. 



OREOHELIX YAVAPAI VAUXAE, new subspecies 



Plate 1, Figures 1, 2,3, 11 



Shell w^ith spire depressed, flatly conic, height of spire and depth 

 of base about equal. Whorls sharply angulate and bearing on the 

 periphery a prominent white carina which resembles a cord of twisted 

 fibers because of the growth lines crossing it obliquely. This carina 

 begins when the shell has about two whorls. The upper part of the 

 later w^horls is attached to the under side of the carina, which there- 

 fore fills the suture. It continues on the periphery of the body whorl, 

 but is less marked behind the aperture. Early shell brownish with 

 a few transverse growth lines and a little later with obscure elevated 

 striae, which are obscurely granular and become stronger until about 

 2^/^ whorls are completed. At that point the brownish color ceases 

 and is followed by the pale flesh color of the adult shell, and there 

 are several rows of granules spirally arranged, and the whole surface 

 covered with very fine spiral striae, which are most prominent just 

 above the carina. Transverse sculpture of rather strong, retractive 

 growth lines. Umbilicus very wide, showing all the whorls. Base 

 rounded, smoother than the spire, with several spiral rows of minute 

 granules. Aperture continuous, nearly round, lip simple, oblique, 

 very slightly angulated by the periphery, a thick callus across the 

 body whorl. Upper edge of body whorl slightly descending from the 



No. 2802.— Proceedings U. S. National Museum, Vol. 76, Art. 5 



58643—29 1 



