332 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



whorls and measures: Altitude, 10.0 mm.; greatest diameter, 22.5 

 mm.; least diameter, 19.6 mm. 



The other specimens yield the following additional measurements 



This race of Oreolielix yavapai Pilsbry is the most northern one so 

 far reported. It differs from the typical form, which comes from 

 "Purtjnuan's Ranch on Oak Creek, Yavapai County, about 40 

 miles from Jerome, Arizona," in being larger, more solid and more 

 acutely keeled. Dr. Henry A. Pilsbry gives the following measure- 

 ments of his 0. yavaimi: Altitude 8.7-9.5 mm.; greatest diameter 

 15.2-16.6. 



Our race appears nearest related to Oreolielix yavapai angelica 

 Pilsbry and Ferriss, which v/as collected by these authors near the 

 base of the Crossbed Sandstone, Bright Angel Trail, Grand Canyon, 

 Colorado. Of this Doctor Pilsbry has kindly sent me eight specimens 

 for the collection of the United States National ^Museum (Cat. No. 

 215085), which yield the following measurements: 



In addition to the differences expressed by the measurements, 

 our shell has the peripheral keel oven more compressed than Oreo- 

 helix yavapai angelica Pilsbry and Ferriss. 



