ORTHOPTEEA OF INDIANA. 333 



Our members of this sub-family for the most part frequent the 

 borders of marshes and damp prairie meadows, making their homes 

 among the tall rank grasses and sedges which there abound. They 

 usually move by flying, making no noise while on the wing. One 

 or two species, however, delight in sandy or clayey places, where 

 clumps of bunch and wire grass furnish them protection and food. 

 Their inner wings are never bright colored and showy as in the next 

 sub-family, and their tegmina have remained a green or straw color 

 in order to harmonize with their chosen abiding places. The males 

 stridulate, or call the opposite sex to them, only when at rest by rub- 

 ing the inner surface of the hind thighs against the outer surface of 

 the wing covers. No one of our species occurs in sufficient numbers 

 to do much damage to vegetation, and some of them are among 

 the least common of the Acridida^. The winter of all is passed in 

 the egg stage. 



Thirty-eight genera and 90 species of Tryxalince are listed by Scud- 

 der from the United States, mostly from the region west of the Mis- 

 sissippi Eiver, and one or two additional species have been described 

 since his catalogue was issued. Of these, but nine species, repre- 

 senting eight genera, have as yet been taken in Indiana, though 

 several others may in time be found to inhabit limited areas of the 

 'State. Our genera may be separated by the following table: 



KEY TO INDIANA GENERA OF TRl'XALIN^. 



a. Foveolae of the vortex wanting or invisible from above; face very 

 oblique. 



h. Sides of the fastigium sti-ongly rounded, so that the apex is in 

 no way acuminate; antennfie strongly flattened at the base; 

 pronotum with the lateral lobes vertical and straight and the 

 lateral carinse parallel; median carina of the pronotum cut 

 much behind the middle; tegmina fully developed, acuminate 



or angulate at apex XVII. Tryxalis, p. 234 



hh. Sides of the fastigium straight or gently rounded so that the, 

 apex is more or less acuminate; antennae variable; pronotum 

 with the lateral lobes less distinctly vertical; the lateral 

 carina? gently or strongly sinuate near the middle (except in 

 Dicromorpha); median carina of the pronotum cut in or but 

 little behind the middle; tegmina rounded at apex, 

 c. Hind tibia armed with 18 to 21 spines on the outer mai'- 



gin XVIII. Syebula, p. 23G 



cc. Hind tibia armed with not over 15 spines on outer margin. 

 d. Antennae relatively short, at most but little longer 

 than head and pronotum together; fastigium of ver- 

 tex with no distinct median carina. 



45-Geol. 



