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Acrididae. 



Sub-families, Genera and Species. 



Sub-Families. 



A. — Pronotum extending over abdomen; claws of tarsus without 



pulvillus; size small — Tettiginae. 

 AA. — Pronotum not extending over abdomen; claws of tarsus with 

 pulvillus; Size larger. 

 B. — Prosternum with tubercle — Acridinae. 

 BB. — Prosternum without tubercle. 



C. — Vertex and front of head meeting at an acute angle — 



Tryxalinae. 

 CC. — Vertex and front rounded — Oedipodinae. 



Genera of the Tettiginae. 



A. — Antennae 12-jointed and pronotum rounded — Batrachidea. 

 AA. — Antennae 13-14-jointed; pronotum horizontal — Tettix. 

 AAA. — Antennae 22-j.ointed; pronotum horizontal — Tettigidea. 

 (For species see Blatchley's Orthoptera of Indiana.) 



Genera of the Acridinae. 



A. — Wings as long or longer than the abdomen. 



B. — Pronotum sloping from median carina; extremity of abdomen 



in males not swollen — Acridium or Schistocerca. 

 BB. — Pronotum flattened; extremity of abdomen in males swollen 

 — Melanoplus. 



Species of Acridium. 



A. — -Size large; antennae rather short — A. americana. 

 AA. — Size medium; antennae longer. 



B. — Colour yellowish brown or olive green — A. alutacea. 

 BB. — Colour rusty brown; no yellowish stripe on dorsum — A. rubig- 

 itiosa. 



Species of Melanoplus. 



A. — Apex of last abdominal segment of male distinctly notched. 



B. — Length of body to tip of wing covers 29-35 mm — M. spretus. 

 BB. — Length of body to tip of wing covers 23-26 mm. — M atlanis. 

 AA. — Apex of last abdominal segment of male entire, or at least 

 obscurely notched — M. bivittatus. 

 \. — Anal cerci enlarged at apex. 

 2. — Anal cerci tapering. 



