222 OETHOPTEEA. 



dorsal carinae smooth. Frontal costa plane above 

 the ocellus, narrowed below and sulcate. Hind tibiae 

 seven-spined externally Osmilia, Stal. 



181 (180). Tegmina abbreviate, lateral. Hind femora with the 



dorsal carinse tuberculate or toothed. Frontal costa 

 sulcate throughout, of about equal width. Hind tibiae 

 eight-spined externally Tjsnophaus, Bruner. 



182 (179). Frontal costa obliterated towards the clypeus. Tegmina 



lobiform. Eyes broader. 



183 (184). Pronotum with the transverse sulci faint or obsolete; 



the body glabrous Perixerus, Gerstaecker. 



184 (183). Pronotum with the transverse sulci strongly impressed ; 



the body not glabrous Dactylotum, Charpentier. 



185 (178). Frontal costa plainly produced between the antennae. 



Body apterous or the tegmina alone present, lobi- 

 form, lateral. 



186 (187). Posterior femora with the lower margin sinuate before 



the genicular lobes. Tegmina lobiform Agesander, Stal. 



187 (186). Posterior femora with the lower margin straight. 



Tegmina absent, linear, squamiform, or spatulate. 



188 (189) . Pronotum cylindrical Rhytidochrota, Stal. 



189 (188). Pronotum more or less tectate or cristate. Fastigium 



depressed. 



190 (193). Median carina of the pronotum not greatly elevated, 



only slightly lobate. Body not robust, the tegmina 

 present. 



191 (192). Male cerci furcate; tegmina squamiform, very minute, 



not attaining the hind margin of the mesothorax ; 



antennae long and slender Rhachicreagra, Rehn. 



192(191). Fastigium horizontal; the male cerci acuminate; teg- 

 mina broadly spatulate, reaching the hind margin of 

 the first abdominal segment ; antennae short and 

 fairly heavy Microtylopteryx, Rehn. 



193 (190). Median carina of the pronotum strongly serrato-lobate. 



Body robust, apterous [Polysarcus, Saussure.*] 



* The genera Pedies and Pcepedetes of Saussure are so poorly characterized that it has been impossible to 

 locate them in this synoptic table. They probably belong in the neighbourhood of Dactylotum, but this is 

 only conjecture on the part of the present writer. Walker's Calacris has also been excluded from the table 

 for the same reason. It is perhaps related to, or even identical with, Proctohbus, Saussure. The species, 

 however, seems to be distinct from P. mexicanus, Sauss., and the others that are described on a succeeding 

 page of the present work. It has also been found necessary to place Saussure's genus Pegasidion among the 

 doubtful ones, and include it here on account of the clause " prosternum cornu cylindrico armatum," contained 

 in the description of the genus. None of the genera and species here referred to have been recognized among 

 the material studied for this enumeration. 



