26 OETHOPTEKA. 



Synopsis of the Genera. 



A. Foveolae of the vertex invisible from above or wanting, their 

 plane forming a right or acute angle with the plane of the 

 fastigium ; face, as a rule, much more oblique than in the 

 alternate category. 



b. Sides of the fastigium strongly rounded, the apex not 



acuminate; antennae ensiform; tegmina acuminate or 

 angulate at base; apical angles of posterior femora hori- 

 zontally produced, acuminate. 



c. Fastigium of the vertex greatly produced, as long as or 



longer than the eye, its sides on the basal half subparallel ; 

 face excessively oblique, the eyes nearly longitudinal. 

 d. Foveolae of the vertex absent; tegmina much abbre- 

 viated, spines on outer margin of hind tibiae numerous, 

 about 25 ; subgenital plate of male abdomen greatly 



lengthened Rhadinotatum, McNeill. 



dd. Foveolae of the vertex narrow, elongate ; tegmina passing 

 the tip of abdomen ; spines on outer margin of hind 

 tibiae less numerous, about 16; subgenital plate of 



male abdomen only moderately elongate Achurum, Saussure. 



cc. Fastigium of the vertex subtriangular, not greatly pro- 

 duced, distinctly shorter than the eyes, the sides converg- 

 ing from the base ; face less oblique, the eyes distinctly 

 oblique. 



d. Larger, general colour green Metaleptea, Brunner. 



dd. Smaller, general colour testaceous or ferruginous . . . [Orphula, Stal.] 



bb. Sides of the fastigium straight or but gently rounded, the 

 apex more or less acuminate, tegmina apically rounded 

 or obliquely truncate; apical angles of posterior femora 

 roundly deflexed. 



c. Hind tibiae armed with numerous spines on outer margin, 



numbering 12-20, usually 16-20. 

 d. Antennae long and ensiform ; presternum with a distinct 

 tubercle ; lateral carinae of pronotum wanting or deve- 

 loped, diverging but little when present. 

 e. Lateral carinae present; hind tibiae with 18-20 spines 



in outer row Mermiria, Stal. 



ee. Lateral carinae wanting; hind tibiae with 12-15 spines 



in outer row Paropomala, Scudder * 



dd. Antennae shorter, filiform or more or less flattened 



* Scudder places this genus in the subfamily Acridiinas, close to Leptysma ; but, according to the writer's 

 judgment, it should be included with the Tryxaliuae. For a further discussion of the matter, vide infra. 



