90 PROCEEDINGS OF THE ACADEMY OF [March^ 



ward to Black Canyon (Reed's) and Morgan Creek. Taken at 

 15 stations. 



This is a common shell at high elevations, in the mountains north 

 of Hillsboro Peak. Especially in the labyrinth of canyons forming 

 the heads of Las Animas Canyon, but also on the western slope of 

 the range. Most of the stations are between 8,000 and 9,000 feet. 

 It was found mainly under dead wood on shady and rather humid 

 slopes. 



Very often the inner of the two basal teeth is wanting, being 

 reduced to a sloping callus against the other tooth. 



Ashmunella cockerelli n. sp. PI. VII, figs. 3, 4,9. 



The shell is umbilicate (umbilicus between one-fifth and one-sixth 

 the total diameter, enlarging in the last half whorl, rather tubular 

 further in); depressed; carinate at the periphery; the shape recalling 

 Polygyra corolinensis and obstricta; wood-brown above, usually 

 somewhat paler at the base, having a buff streak indicating a former 

 resting stage about the middle of the last whorl. Surface lusterless 

 except the earliest whorls. Sculpture of close-set, irregular pebble-like 

 granules on the last whorl, finer on the whorl preceding, before which 

 it is finely striate and slightly punctate, the first Ih whorls smooth 

 and glossy. The inner whorls are convex, the penult whorl flattened, 

 the last somewhat convex above, but excavated on both sides of the 

 strong peripheral keel. It is rather swollen below the keel, particu- 

 larly in the last half. It descends shortly in front, and is guttered 

 behind the outer and l)asal margins of the lip. The aperture is very 

 oblique, subcircular and toothless. Lip is reflected and somewhat 

 thickened within. 



Alt. 8.2, diam. 16.4 mm.; 5| whorls (type, figs. 3, 9). 

 " 7.2, " 17.8 " 



South of Sawyer's Peak, on slopes of the ravine at Grand Central 

 Mine (Station 20), and in the next two ravines on the trail to the 

 peak (stations 19 and 22). Also further north at Station 12^, a short 

 distance above Spade's cabin. 



This species, which it gives us pleasure to name for Professor 

 T. D. A. Cockerell, is remarkable for its strong carina and roughly 

 pebbly sculpture, which is coarsest on the latter part of the whorl. 

 The upper surface is usually convex, but often nearly flat. The 

 periphery of the penult whorl frequently projects a little above the 

 suture in the individuals with flattened spire. 



