56 GUIDE TO ORTHOPTERA 



A ^. Prosternum unarmed. 



b^. Fore tibiae spined above on both margins. 



c ^ Large bulky insects. Tegmina of ^ almost completely 

 concealed beneath the pronotum ; eyes but little larger than 

 antennal scrobes. . . . A^iabrus Haldeman. 



c ^. Relatively small insects. Exposed portion of J' tegmina 

 half as large as pronotum ; eyes fully twice as large as 

 antennal scrobes. . . Cacopteris Scudder p. p. 



h ^. Fore tibiae armed above on outer margin only, 



c ^ Fore tibiae with several spines above on outer margin, 

 dfi. Fore tibiae with three spines above on outer margin. 

 e^. Legs short, the hind femora scarcely or not extend- 

 ing beyond abdomen ; sm'face of pronotum granulate. 



Peranabrus Scudder. 



e 2. Legs long, the hind femora extending far beyond 



abdomen ; surface of pronotum smooth. 



/'I. Pronotum without distinct lateral carinae, except 



sometimes posteriorly ; a median carina rarely present 



and then weak. 



r/^. Pronotum transversely arched as much on the 

 posterior as on the anterior half. 



h ^ . Ovipositor straight. Cacopteris Scudder p. p. 

 h^. Ovipositor arcuate. Ereinopedes Scudder. 

 g^. Pronotum laterally subangulate posteriorly, 

 and often with a slight median cannula. 



Idiostatus Pictet. 

 /"•^. Pronotum with distinct lateral and median carmae, 

 the latter sometimes weak. 



r/i. Lateral carinae of pronotum parallel or sub- 

 parallel. . . . Steiroxys Hermann. 

 g"^. Lateral carinae approximated in middle of 

 anterior half of pronotum, so as to narrow the 

 dorsum by nearly one half. Idionotus Scudder, 

 d'^. Fore tibiae with four spines above on outer margin, 

 e^ Descending lobes of pronotum long, obliquely 

 decUvent, the dorsum narrow. CUnopleura Scudder. 



