70 



Group 3.-TRIGONOPTERYGINI. 



Trigonopterygidce,, Walk. 



This group is distinguished from the preceding by its broad elytra, ll 

 has no representatives in North America. 



Divis. II.-ORTHOCERIDES. 



In this division tlie head is obtuse or sub-conic ; where it approaches 

 the conical or ])yramidal form it is generally less distinct than in the prece- 

 ding division, and such species are separated from that division l)y the form 

 of the antennae. The face is sub-oblique or vertical ; therefore, the term 

 "oblique," when applied to species or genera of this division, is to be under- 

 stood as limited, and as compai'ed with the vertical face. 



The antennae are generally filiform, the joints cylindrical, or slightly 

 flattened and indistinct ; in a few species they are slightly enlarged near the 

 base ; and in a few instances clavate. 



In the United States Acrididae the genus Oxycoryplms appears to form 

 the connecting link between (his and the previous division, the shape of the 

 head and form of the antennae making it somewhat difhcult to determine in 

 which it should be placed. 



This division is distinguished from the Xiphocer'ules chiefly by the form 

 of the antennae. 



It embraces that portion of the family included by Serville under 



"■' Acrid'ites propric dicti;" and contains but two groups, CEdipodini and 



Acridini 



A. Prosteniuiu smooth or but slightly tuberculate (Edipodini. 



AA. Prosternum' armed with a spine Acridini. 



Group 4.-CEDIP0DINI. 



Mutici, Serv., Scudd ; CEd'qwdidce, Walk. 



This group is distinguished by the vertical or sub-vertical face ; filiform 

 antennae with indistinct joints ; and absence of a prosternal spine, the 

 presternum being either smooth or (in one genus only — Stetlieophyma) slightly 

 tuberculate. Tiiere are some apparent variations from these characters, which 



