142 PROCEEDINGS OF THE ACADEMY OF [Feb., 
Fig. 34.—Bifidaria cochisensis oligobasodon P. and F. Ash Canyon, Huachuca 
Mountains. 
Length 2.6, diam. 1.1 mm. 
ce De ly ce il “é 
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.*° (fig. 35), 
Fig. 35.—Bifidaria prototypus Pils. 
% Proc. A. N.S. Phila., 1899, p. 400. 
