PREFACE. VII 



My work mast have shortcomings and errors ; the subject is by no 

 means an easy one. I only ask that it be accepted as an honest endeavor 

 to advance the study of these neglected but interesting insects. 



The types of all but two or three of the new species described by me, 

 together with my entire collection in this family, will be preserved in 

 the National Museum for future reference and revision. 



S. W. WILLISTON. 

 Yale College, New Haven, Conn., 



June 1, 1886. 



