Sept.,1906.] Bruxer : The Orthoptera of Trinidad. 151 



Group Leptysmini and allies. 



From the collections at hand it would appear that at least one 

 half of the American genera of Acridians with the dilated and acute- 

 edged hind tibiae are represented on the Island of Trinidad. This 

 being true, and because there is likewise a new genus now to be added 

 to the group, a synoptic table of the genera is herewith given : 



Table for the Separation of the American Genera of Leptvsma 

 and Allies.* 



*This table is a modification of Giglio-Tos' (Bolletino dei Musei di Zoologia ed 

 Anatomia comparata della R. Universita di Torino, No. 311, XIII, pp. 40-50, 1898). 



A. Posterior tibire slightly expanding apically, the margins acute. 



/». Mesosternal lobes with their inner edges nearly straight and touching for most 

 of their length. Elytra acuminate. 

 c. Fastigium of the vertex as long as, or longer than, the longest diameter 

 of eyes. 

 d. Fastigium of the vertex furnished with decided longitudinal grooves 

 or sulci. 



e. With but a single profound sulcus Leptysma Stal. 



ee. With four such narrow but well-defined sulci. 



Leptysmina G. Tos. 

 dd. Fastigium of the vertex without definite longitudinal sulci. 



Cylindrotettix n. gen. 



cc. Fastigium of the vertex shorter than the eyes Arnilia Stal. 



bb. Mesosternal lobes more or less distant. Tegmina subacuminate or rounded at 

 apex. 

 c. Posterior margin of the pronotum rounded. 



d. Tubercle of the presternum transverse, broad, the ajex truncate. 



Oxybleptella G. Tos. 

 dd. Tubercle of the pronotum conical, more or less acute. 



e. Body very graceful or slender. The front strongly oblique. 

 Head much exserted, conical. Antennae distinctly ensiform. 

 Eyes rather elongate, viewed from above strongly convergent, 

 meeting at an acute angle. Pronotum distinctly di'ated pos- 

 teriorly, the lower edge of sides straight, oblique. Tegmina 



somewhat dilated toward apex Inusia G. Tos. 



ee. Body heavier. The front less oblique. Head only gently ex- 

 serted, not conical. Antenme filiform, or a little suben- 

 siform. Eyes not at all or but little elongated, when 

 viewed from above slightly convergent, forming an obtuse 

 angle. Pronotum not or but little dilated posteriorly ; 

 the lower edge of sides straight on posterior half, emargi- 

 nate on anterior half. Tegmina narrow towards apex. 



