OREGON STATE MONOGRAPHS 



STUDIES IN ZOOLOGY 

 Number 2., March 1940 

 OREGON STATE COLLEGE 



OREGON STATE SYSTEM OF HIGHER EDUCATION 

 Corvallis, Oregon 



Copyright 1940 by 

 IRA N. GABRIELSON 



and 

 STANLEY G. JEWETT 



Printed and Bound in U. S. A. by James, Kerns & Abbott Co., Portland, Oregon. 



