56 GUIDE TO ORTHOPTERA 



A 2 . Prosternum unarmed. 



b l . Fore tibiae spined above on both margins. 



c l . Large bulky insects. Tegmina of almost completely 

 concealed beneath the pronotum ; eyes but little larger than 

 antennal scrobes. . . . Anabrus Haldeman. 



c 2 . Relatively small insects. Exposed portion of tegmina 

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

 antennal scrobes. . . Cacopteris Scudder p. p. 



b 2 . Fore tibiae armed above on outer margin only. 



c 1 . Fore tibiae with several spines above on outer margin. 

 d l . Fore tibiae with three spines above on outer margin. 

 e 1 . Legs short, the hind femora scarcely or not extend- 

 ing beyond abdomen ; surface of pronotum granulate. 



Peranabrus Scudder. 



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

 abdomen ; surface of pronotum smooth. 

 f l . Pronotum without distinct lateral carinae, except 

 sometimes posteriorly ; a median carina rarely present 

 and then weak. 



ff 1 . Pronotum transversely arched as much on the 

 posterior as on the anterior half. 



h l . Ovipositor straight. Cacopteris Scudder p. p. 

 h' 2 . Ovipositor arcuate. Eremopedes Scudder. 

 g<*. Pronotum laterally subangulate posteriorly, 

 and often with a slight median carinula. 



Idiostatus Pictet. 



/ 2 . Pronotum with distinct lateral and median carinae, 

 the latter sometimes weak. 



ff l . Lateral carinae of pronotum parallel or sub- 

 parallel. . . . Steiroxys Hermann . 

 <7 2 . Lateral carinae approximated in middle of 

 anterior half of pronotum, so as to narrow the 

 dorsum by nearly one half. Idionotus Scudder. 

 d 2 . Fore tibiae with four spines above on outer margin. 

 e 1 . Descending lobes of pronotum long, obliquely 

 declivent, the dorsum narrow. Clinopleura Scudder. 



