ACKNOWLEDGMENTS. 



This paper was started and completed under the direction of 

 Prof. S. J. Hunter, head of the department of entomology in 

 Kansas State University. To him the writer is greatly in- 

 debted for making this work possible and for his ever readiness 

 to help with suggestion or with needed equipment or material. 

 Dr. H. B. Hungerford, of the same department, has also been 

 keenly sympathetic and helpful during the carrying on of the 

 work. 



Prof. Herbert Osborn kindly determined much material 

 for me, as did Dr. E. D. Ball. I am especially indebted to the 

 latter for much help received from him during a period of six 

 weeks spent at Ames. During that time he gave me many help- 

 ful suggestions out of his large acquaintance with this group, 

 and turned over his whole collection and library, as well as the 

 collections of the Iowa State Agricultural College, for my use 

 and study. I was thus enabled to examine many of the Osborn 

 and Ball types, Doctor Ball's individual types, and as many of 

 Van Duzee's types as are in the college collection. It would be 

 hard to conceive of any one being more free and ready to help 

 with the results of their years of labor and study. 



Needless to say, many papers on the CicadellUhe have been 

 freely used. The bibliography given would have been impos- 

 sible without Van Duzee's wonderful catalogue, with the ex- 

 ception here and there of a few papers on the economic phase, 

 and of the papers which have appeared since the catalogue was 

 issued. Besides the catalogue, we have used freely the papers 

 written jointly by Osborn and Ball, as well as the individual 

 papers of each. Van Duzee's writings on the family have been 

 very helpful, as have De Long's paper on the Tennessee species 

 and on the genus Chlorotettix. 



The writer was fortunate to start his study of this group 

 with a very large collection already gathered together from all 

 over the state. Credit should be given to several of those whose 

 locality records are here being used. Prof. F. H. Snow's name 

 appears on many of the specimens collected in Kansas. The 

 records of Pottawatomie county are practically all those of Mr. 

 F. F. Crevecoeur. Mr. E. S. Tucker took many species from 



