1915.] NATURAL SCIENCES OF PHILADELPHIA. 383 
Zonitoides minuscula alachuana (Dall). 
Dragoon Mountains: Stations 1, 63, 10, 15, 26, 28, 29. 
Striatura milium meridionalis P. and F. 
Dragoon Mountains: Stations 1, 6, 10, 29. 
Euconulus fulvus (Mill). 
Dragoon Mountains: Stations 1, 10, 15, 28 and E. f. alaskensis, 
Station 29. 
ENDODONTID&. 
Pyramidula cronkhitei (Newc.). 
Dragoon Mountains: Stations 28, 29. 
Radiodiscus millecostatus Pils. and Ferr. 
Dragoon Mountains: Stations 1 and 10; rare. 
Helicodiscus arizonensis Pils. and Ferr. 
Dragoon Mountains: Stations 1, 63, 10, 28, 29. 
Punctum californicum Pils. 
Dragoon Mountains: Station 10, in the amphitheatre or upper 
basin of Tweed Canyon. The specimens are a little more openly 
umbilicate than the type, but the riblets are more unequal than in 
P. pygmeum, and spiral lines are scarcely discernible. 
SUCCINEIDZ. 
Succinea avara Say. 
Dragoon Mountains: Stations 2, 3; single dead specimens. 
FERUSSACIDA. 
Cochlicopa lubrica (Mill.). 
Dragoon Mountains: Stations 1, 6, 63, 10, 15, 28, 29. Abundant. 
PUPILLIDA. 
Bifidaria ashmuni Sterki. 
Dragoon Mountains: Stations 1, 3, 6, 10, 11, 15, 25, 26, 29. 
Bifidaria perversa Sterki. 
Dragoon Mountains: Stations 2, 3, 22. 
Bifidaria dalliana Sterki. 
Dragoon Mountains: Stations 3, 6, 26. 
Bifidaria pilsbryana Sterki. 
Dragoon Mountains: Stations 1, 2, 10, 11, 15, 18, 25, 28, 29. 
Vertigo coloradensis arizonensis P. and V. 
Dragoon Mountains: Station 25. 
