232 PROCEEDINGS OF THE ACADEMY OF [Mch., 



There is a faint, hardly noticeable basal prominence, but nothing to 

 be called a tooth. There is no parietal tooth, and the callous between 

 the lip-ends is very thin. 



Alt. 5.5, diam. 11 mm. 



Sierra Blanca, on the highest summit, three found under a rock, 

 elevation 11,092 feet (C. H. T. Townsend). 



One of the co-types of this very distinct form is figured, No. 73,558, 

 A. N. S. P. 



Ashmunella pseudodonta (Dall). PI. XII, figs. 15, 16, 17, 18. 



Polygyra pseudodonta Dall, Proc. U. S. Nat. Mus., XIX, 1896, p. 343 (White 



Oaks, New Mexico). 

 Ashmunella pseudodonta Dall, Proc. U. S. Nat. Mus., XXIV, 1902, p. 500, 



PL 27, figs. 13, 1.5; PI. 28, figs. 7. 

 Ashnmnella pseudodonta Pils. and Ckll., Proc. Acad. Nat. Sci. Phila., 1899, 



p. 192; Murdoch, Jour, of Malac, VIII, p. 79, PI. 7, figs. 1-7 (anatomy). 



This species differs from those of the Sierra Blanca chiefly by its more 

 depressed shape and the bifid basal callous, which is split into two low 

 denticles like some of the subspecies of ,4. thomsoniana. The compara- 

 tively short duct of the spermatheca shows A. pseudodonta to be much 

 more closely related to A. rhyssa than to A. thomsoniana. Five speci- 

 mens of the original lot collected by Mr. Ashmun at White Oaks, New 

 Mexico, measm'c: 



Alt., 7 7 6.5 6.4 6.4 mm. 



Diam., 13 12.7 12.7 12.2 12 " 



Two specimens found with A. p. capitaneyisis measure: 

 Alt. 7 6.7 mm. 



Diam.. 13.9 13.5 " 



The internal anatomy has been well described and figured by Mur- 

 doch. 



Ashmunella pseudodonta capitanensis Ashm. and Ckll. PI. XII, figs. 21-23. 



A. p. capitanensis Ashmun and Cockerell, Nautilus, XII, p. 131, March, 1899. 

 The shell is depressed, glossy, brown, with weak irregular growth- 

 wrinkles and fine, close incised spirals. The spire is very low conic, 

 Wliorls 5^, quite convex, the last wide, rounded peripherally, swollen 

 above behind the deep constriction behind the lip. The aperture is 

 quite oblique, the lip either brown-tinted throughout or white. Within 

 the basal margin there is a loir, very iccakly bifid callous, often hardly 

 noticeable. There is a very small parietal tooth in four out of six 

 specimens examined. The umbilicus is small and deep within, enlarg- 

 ing at the last whorl, rather broadly exposing the pemdtimate whorl. 



