142 



PROCEEDINGS OF THE ACADEMY OF 



[Feb., 



Fig. 34. — Bifidaria cochisensis oligobasodon P. and F. Ash Canyon, Hu'achuca 



Mountains. 



Length 2 . 6, diam. 1 . 1 mm. 

 u 2.1, " 1 



Ash Canyon, Huachuca range. Types No. 97,444 A. N. S. P., 

 cotypes in Ferriss coll. 



This form would be considered specifically distinct from cochisensis 

 were it not approached by a small form of that species from Tanner 

 Canyon, which has weaker teeth than the larger typical cochisensis. 

 B. c. oligobasodon stands very near B. prototypus Pils. 30 (fig. 35), 



Fig. 35. — Bifidaria prototypus Pils. 



30 



Proc. A . N. S. Phila., 1899, p. 400. 



