4 THE UNIVERSITY SCIENCE BULLETIN. 
Hemiptera which has facilitated greatly the preparation of 
this work. 
To Dr. P. W. Claassen and Mr. Clyde Hamilton, of Cornell 
University, and to Miss Ruby Hosford, Dr. C. P. Alexander, 
Dr. Paul B. Lawson, Mr. Raymond Beamer and Miss Ger- 
trude Standing, of Kansas University, for special assistance 
from time to time, and to many others, who, one way or an- 
other, have contributed to the completeness of this work, he 
is most duly grateful. 
