94 



PROCEEDINGS OF THE ACADEMY OF 



[March, 



lines and faint traces of microscopic spirals, and on its last third 

 there are usually several small spiral threads. The young stages 

 have an acutely angular periphery, which becomes bluntly angular 

 on the last whorl, which descends very little in front. The aperture 

 is strongly oblique. 



Alt. 12, diam. 21 mm. (type). 

 '' 12, " 22 " 

 " 13.2, " 20 " 



Black Range, at stations 44, 45 and 48, head of Morgan Creek; 

 42, Black Canyon, 4 miles below Reed's ranch; 50 and 51, on Dia- 

 mond Creek, about 3 miles below the summit, and again about half 

 way clown. 



Fig. .3. — Reproductive organs of Oreohelix swopei. b, the penis opened, showing 

 fleshy organs in the swollen portion, c, the penis and epiphallus stretched 

 straight. 



This snail is named in honor of Dr. S. D. Swope, of Deming, New 

 Mexico, in acknowledgment of his interest in scientific matters and 

 his kindly help in furthering our investigation. That we visited 

 the Black Range at all was due to his alluring picture of its beauties. 



In the field this shell was taken for 0. s. depressa. It was found 

 among rocks on the well-shaded slopes of ravines, usually with 

 0. cooperi and Ashmunella. The absence of spiral striation on the 

 last whorl aroused suspicion of the reference to 0. s. depressa, and 

 on closer study it was found to differ by the far smoother embryonic 

 shell, and especially by the soft anatomy, the male organs being 

 quite different in the two species. In 0. s. depressa the lower part 



