PROC. ACAD. NAT. SCI. PHILA. 1905. 



PLATE XVII. 



11 



13 



^^'-Tf^ig^ ^ 



14 



& 



^'^^■' 



10 



15 



16 



17 



18 



12 



19 





20 



24 



21 ^1 22 — 23 



PILSBRY. MOLLUSCA OF THE SOUTHWESTERN STATES 



