Number 15. December 16, 191 5. 



OCCASIONAL PAPERS OF THE MUSEUM OF 

 ZOOLOGY 



UNIVERSITY OF MICHIGAN 



Ann Arbor, Michigan. Pubushe-d by the University. 



A LIST OF SHELLS COLLECTED L\ ARIZONA, NEW 



MEXICO, TEXAS AND OKLAHOMA 



BY DR. E. C. CASE. 



By Bryant Walker 



During several of his recent palaeontological explorations 

 in the western states, Dr. E. C. Case of the Department of 

 Geology, University of Michigan, very kindly took the trouble 

 to collect samples of drift from many of the localities visited 

 by him. The net result is a valuable and interesting contribu- 

 tion to our knowledge of the distribution of the species belong- 

 ing to the arid lands of the west, and especially so because very 

 many of the localities have never been visited by conchologists 

 and are not likely to be on account of the local conditions. 



The writer is indebted to Dr. V. Sterki and Dr. George 

 H. Clapp for the identification of all of the land species, except 



Scientific Papers of thb University of Michigan No. i6. 



