1909. ] NATURAL SCIENCES OF PHILADELPHIA. 515 
Bifidaria quadridentata Sterki. 
Wickersham’s, Miller Canyon. One specimen. 
Bifidaria ashmuni Sterki. 
Ash Canyon. 
Bifidaria cochisensis Pils. and Ferr. 
Tanner Canyon, abundant. This form and the following will be 
described in the next paper of this series, in connection with a general 
review of the group of B. ashmunv. 
Bifidaria cochisensis oligobasodon Pils. and Ferr. 
Ash Canyon. 
Bifidaria pilsbryana Sterki. 
Wickersham’s, Miller Peak. 
Bifidaria tappaniana (C. B. Ad.). 
Tanner Canyon, 6,000 feet; also San Pedro drift at Benson." 
Vertigo ovata Say. 
Ash Canyon; Tanner Canyon, 6,000 feet; also San Pedro drift at 
Benson. 
Vertigo modesta parietalis Anc. 
Wickersham’s, Miller Peak. 
Vertigo conoinnula Ckll. 
Wickersham’s, Miller Peak; one immature shell. 
Vertigo milium Glad. 
Tanner Canyon, 6,000 feet; drift of San Pedro river at Benson. 
FERUSSACIDA. 
Cochlicopa lubrica (Mill.). 
Tanner Canyon, 6,000 feet ; Carr Canyon ; Wickersham’s, Miller Peak. 
LYMN AIDA. 
Lymnea parva Lea. 
Ash Canyon; a few very young specimens. 
PHYSIDZ. 
Physa virgata Gld. 
Small, slender, long-spired examples, clearly of the virgata type, were 
taken in Tanner Canyon, in a spring at about 6000 ft. 
| Bifidaria pentodon (Say) was taken in San Pedro drift at Benson, Cochise 
county, Arizona. 
