40 IOWA ACADEMY OF SCIENCES. 



A GENERIC SYNOPSIS OF THE NEARCTIC PENTA- 

 TOMIDAE. 



BY H. E. SUMMERS. 



Practically the only keys for determining the genera of our 

 Pentatomidge are those of St^l. These cover only certain 

 divisions of the family, and even in these divisions many 

 recently established genera are not included. His works are, 

 moreover, usually not accessible except to the special student 

 of the Heteroptera, and even when accessible, the fact that 

 they deal with a fauna much more extended than our own, 

 makes them too cumbersome for the ready use of the general 

 student. For these reasons it is thought that a key limited to 

 our fauna and brought up to date may be a convenience. 



For the chief groups the classification of Stiil, followed in 

 the main by Uhler in this country, has been adopted, although 

 the present writer has grave doubts of the natural character 

 of some of the divisions. In consequence of the introduction 

 of new genera it has been found necessary to modify consider- 

 ably Stal's definitions of some of the groups. All the 

 recorded Nearctic genera have been examined. Thanks are 

 due Dr. S. A. Forbes for placing freely at my disposal the 

 material of the Illinois State Laboratory of Natural History, 

 and to Mr. E. D. Ball, of the Colorado State College of Agri- 

 culture, for the loan of specimens. 



TABLE OF SUB-FAMILIES AND GENERA. 



A. Tarsi 3-jointed. 



B. BucculaB converging caudad, caudal ends united; basal 



segment of rostrum thickened. (Sub-family Asoi)i)i(e.) 



C. Pre-femora armed with a spine or acute tubercle 



below. 



D. Scutellum large, broad, extending almost or 



quite to apex of abdomen; frena never extending 



more than a third the length of scutellum. 



Stiretrus. 



