320 PROCEEDLNGS OF THE ACADEMY OF [Nov.-DeC, 



Alt. 11.5 diam. 22.8 mm, 5| whorls. 

 u j^ u 21 '' 5f 



" 8.5 " 18.3 " 5| 



Extremes of size, Station 86. 



Alt. 11 diam. 22.8 mm. 5f whorls. 

 " 10 '' 19.5 '' 5f 



-4. mogoUonensis differs from A. c/jmca/iMana b}' the very small and 

 short penis, scarcely differentiated from the epiphallus; the absence 

 of a penial retractor muscle; and the more capacious spermatheca, 

 which is sacculate distally in some individuals. There are also dif- 

 ferences in the proportions of the organs, but whether constant or 

 not can be determined only by measuring a long series. In both the 

 epiphallus is very long. The shells can be distinguished by the 

 minute but deeply engraved spiral lines of A. mogoUonensis. 



Other species of Ashmunella from the Mogollon Mountains were 

 described in Nautilus XXIX, 1915, as follows: 



Ashmunella tetrodon Pils. & Ferr. Dry Creek. 



Ashmunella tetrodon mutator Pils. & Ferr. Dry Creek, 



Ashmunella tetrodon inermis Pils. & Ferr. Dry Creek. 



Ashmunella danielsi Pils. & Ferr. Cave Spring Canyon. 



Ashmunella danielsi dispar Pils. & Ferr. Little Whitewater Creek. 



Oreohelix cooperi (W. G. "ti.). P). VII, figs. ] to 0;. 



Mogollon Mountains, Socorro Co., New Mexico: Willow Creek, 

 Stations 46-48, at from about 8,300 to nearly 9,000 ft.; Silver Creek 

 and along the Bursam Road (above Mogollon), at about 7,500 to 

 9,000 ft., Stations 39, 40, 42, 42^, 43, 44; also Station 35. 



The specimens from these localities closely resemble those figured 

 by us from the Black Range, N. M. (in these Proceedings for 1917, 

 pi. 9, figs. 5-9), but there is greater variation in contour, as in 

 pi, VII, figs. 6, 6a from Station 42|, near the crest of the range, 

 measuring 



Alt. 13, diam. 21 mm. 

 " 16.5, '' 20 " 



The commonest form is like that shown in pi. 9, fig. 7 of our paper 

 of 1917; the size generally from 21 to 23 mm. diam. A large shell 

 from Station 48 measures, alt. 16.4, diam. 23.3 mm. At Stations 

 39 and 40 they are smaller, diam. 18 to 20 mm. The size is inde- 

 pendent of elevation, as there are larger shells both above and below 

 these stations in the Willow Creek region. 



In Arizona the same "Black Range form" of cooperi was found 

 on the southern slope of the Blue Mountains, Station 59 (1913), 



