52 GUIDE TO ORTHOPTERA 



the remainder. Many other groups occur in tropical America ; 

 none of ours are peculiar to the United States, and with a single 

 exception, where two genera occur, each of these groups is rep- 

 resented .by a single genus. 



Groups of Phaneropterinae. 

 a ^ Fore coxae unarmed. .... Odonturae. 



a '^. Fore coxae bearing a spine. 



b'^. Fore and middle tibiae sulcate or plane above, but acutely 

 margined, the outer margin spinulose or unarmed. 



ci. Fastigium of vertex scarcely deflexed, acuminate, no 

 broader than the first antennal joint. 



d'^. Tegmina naiTow, the hind margin sinuate ; genicular 

 lobes of hind femora armed with a long pointed spine ; 

 pronotum subsellate. .... Hormiliae. 



d'^. Tegmina broader, the hind margin straight or rounded ; 



genicular lobes obtuse or armed with a short spine ; 



jDronotum not at all sellate. . . Scadderiae. 



c ^. Fastigium of vertex deflexed, obtuse, much broader than 



the first antennal joint; metasternum truncate or with 



rounded lobes. ..... ArtxhlycoTyphae. 



b ^. Fore and middle tibiae smooth above, without angular 

 margin, generally unarmed above ; metasternum wdth elon- 

 gated lobes. ...... Microcentra. 



Odonturae. 

 This group is represented by a single genus, Dichopetala Brun- 

 ner, one species of which occurs in Texas. 



Hormiliae. 

 This group is also represented by a single genus, Arethaea 

 Stal (Aegipan Scudder) which has three or four species in the 

 extreme southern states from Georgia to Arizona. 



Scudderiae. 

 Two of the six genera are represented in our fauna. 



