300 The Ohio Journal of Science [Vol. XVI, No. 7, 



other Homopterous families. Very little work has been done 

 on the anatomy of the Jassids, and as far as the writer is aware, 

 no complete treatment of any phase of the morphology has yet 

 been offered. Considerable work has been accomplished on 

 the other Auchenorrhynchous families by Muir, Kershaw, 

 Licent, Pantel, Bugnion, Sulc and others, but the only treat- 

 ment of the Jassoid anatomy is to be found in the general dis- 

 cussions of systematic works on the group. Thus the works of 

 Signoret, Burmeister, Flor, and Melichar contain general 

 discussions of the external anatomy, which are necessary for 

 taxonomic purposes. The wings and their structure have been 

 ably treated by Metcalf, and only mention will here be made 

 of this phase. 



Since the only work on the external anatomy of the Jassoidea 

 has been done by systematists and for taxonomic purposes, 

 Professor Osborn suggested to the writer that an investigation 

 into the morphology of the group would be of some avail, and 

 accordingly the work was undertaken. The scope of the inves- 

 tigation is confined to the four families. A common and seem- 

 ingly generalized species was selected from each family and in 

 the main the studies here noted were conducted on these. For 

 the Bythoscopidae, Agallia sanguinolenta was selected chiefly 

 because the material, both adult and nymph, was abundant 

 and readily obtainable; the same may be said of Draecula- 

 cephala mollipes for the Tettigoniellidas, Deltocephalus inimicus 

 for the Jassidee, and Empoasca mali for the Typhlocybidae. 

 In many cases species belonging to other genera were studied 

 and compared with the above where such was necessary. 

 To Professor Osborn the writer wishes to express his indebted- 

 ness for directing the investigation, and for helpful criticism 

 and suggestion. 



Methods. 



The material for gross dissection was killed and preserved 

 in a 4 per cent, solution of Formalin and found to be quite 

 satisfactory. Some specimens were killed in hot water and 

 preserved in 70 per cent, alcohol. In many cases material 

 which had recently been collected in the field was killed in 100 

 per cent, alcohol and dissected and examined immediately. 

 All dissection was accomplished by means of a Bausch and Lomb 

 binocular microscope. For the dissection of the smaller 



