218 The University Science Bulletin. 



The material necessary for this study was obtained from the 

 duplicate collection of the University of Kansas entomological mu- 

 seum. A representative number of ovipositors from each of the 

 subfamilies, excepting the Paropinse, was examined, and an attempt 

 made to examine as many different genera and as many species in 

 each genus as possible. In all, representatives of forty-eight genera 

 and ninety-two species were examined and figured. 



The writer wishes to express to Prof. S. J. Hunter his appreciation 

 of the sanction given to this work, and of the necessary time and 

 materials so kindly placed at his disposal. To Prof. P. B. Lawson 

 many thanks are due, both for the conception of the nature of the 

 problem and for the direction of the work to its completion. It 

 was under the able direction of Prof. P. W. Claassen, of Cornell 

 University, that the photography was done. To Prof. H. B. Hunger- 

 ford, Miss Lucy Hackman, Miss Kathleen Doering and Mr. Robert 

 Guntert the writer wishes to express his appreciation for their kind 

 help, suggestions and criticisms. 



THE ABDOMEN OF THE FEMALE. 



(PI. XXI, figs. 1-3.) 



For a study of the abdomen of the female leaf hopper, dried speci- 

 mens of Oncoinetopia lateralis (Fabricius) were used. These were 

 soaked in caustic potash, ten per cent, for twenty-four hours, and 

 drawings and descriptions made from the cleared specimens. 



The abdomen joins the thorax broadly, bulges slightly in the mid- 

 dle, and, from a point a little past the middle, tapers both in width 

 and in height to a blunt, caudal point. A cross section has a general 

 semicircular outline. The tergum is arched, appears dorsally and 

 laterally, and forms the rounded portion of the semicircle, while the 

 pleura and sternum are flat, and form the fiat, ventral portion. The 

 lateral edges of the sternum are bent slightly dorsad at their union 

 with the pleura. The pleura and tergum unite at a distinct but 

 slightly rounded angle. 



Eleven segments can be accounted for in the abdomen. Of these, 

 segments one and two lack distinct pleura, and segments eight to 

 eleven are variously modified as described. 



The tergum of the first segment is partly membranous and partly 

 chitinized. Cephalad, at its junction with the metathorax, it is en- 

 tirely membranous. Caudad, at its junction with the second ab- 

 dominal segment, is a narrow, linear, chitinized sclerite which bears 

 laterally two inwardly projecting processes along its cephalic border. 



