168 



PTJPILLA, AMERICAN. 



Length. 3.3, diam. 1.75 mm. ; 8 whorls. Type, fig. 9. 



Length 4.15, diam. 1.7 mm.; 9 whorls. Yavapai Co. 



Length 3, diam. 1.75 mm. ; 7 whorls. Grand Canyon. 



Pupa syngenes Pils., Nautilus, iv, p. 3, May, 1890, pp. 3, 

 39, pi. 1, f. 7; v, p. 39, pi. 2, f. 1, 2; Proc. A. N. S. Phila., 

 1890, p. 296. BALL, Nautilus, viii, p. 35. PILSBRY & VAN- 

 ATTA, Proc. A. N. S. Phila., 1900, p. 606, with form dextro- 

 versa. DALL, Nautilus, vii, p. 35. Pupitta syngenes PILSBRY, 

 Proc. A. N. S. Phila., 1911, pp. 193-195, f. 7, with P. s. dex- 

 troversa, pp. 193-195, f. 6, 8, and P. s. avus, p. 196, f. 9. 

 Pupilla syngenes dextroversa P. & V., Cockerell, Nautilus, 

 xxv, p. 59. HENDERSON, Univ. of Colo. Studies, x, p. 57. 



NEW MEXICO: San Rafael, Valencia Co. (Ashmun). ARI- 

 ZONA: Holbrook (Ashmun), Black Mesa (Ferriss), Navajo 

 Co.; branch of Chinle Creek, Apache Co. (Ferriss) ; Jerome 

 and Purtyman's ranch, Oak Creek, Yavapai Co. (Ashmun) ; 

 upper levels of the Grand Canyon at Bright Angel trail and 



FIG. l.Pupilla tyngenes Pils. Spectacle Cove near Bass Trail, Grand 

 Canyon. Lengths 3.8, 3.5 and 3.2 mm. 



Bass trail (Pilsbry & Ferriss), and north of the river at 

 numerous places on Powell and Kaibab Plateaus (Ferriss & 

 Daniels). MONTANA: Beaver Creek, a trib. of Little Mis- 

 souri R., in drift debris (Dall). 



This species differs from P. muscorum by the longer pari- 

 etal lamella, the more numerous whorls, the last having a 

 stronger crest and ascending further, the lip less expanded, 

 and the shape, wider above. It is more nearly related to the- 



