1917.] NATURAL SCIENCES OF PHILADELPHIA. 255 



caudal tibise are a striking and distinctive feature in the present 

 insect.^ 



PH^DROTETTIX Scudder. 



1897. PhcEdrotettix Scudder, Proc. U. S. Nat. Mus., XX, p. 22. 

 1897. Rhabdotettix Scudder, ibid., p. 32. 

 1897. Cyclocercus Scudder, ibid., p. 36. 



The genotype of Phcvdrotettix, angustipennis, is inseparable generi- 

 cally from the species of Rhabdotettix, of which palmeri is the genotype. 

 It is true that yalmeri and dumicola^ agree closely in distinctive 

 features of male genitalic development, while in both the tegmina 

 are ovate. In the other species of Phcedrotettix the tegmina are 

 linear, but this difference alone is utterly insufficient to warrant 

 generic separation. The male genitalic development shows widely 

 different features in a number of the species, this being much the 

 greatest in valgus, but in our opinion generic separation is in no case 

 warranted. 



A careful comparison of the genotype, Phcedrotettix angustipennis, 

 with accola, genotype of Cyclocercus, shows also that the latter genus 

 must fall in the present synonymy. The pronotum of accola shows 

 a very slightly heavier median carina than is found in the other 

 species of Phmdrotettix. This feature is of no generic value, nor are 

 the male genitalic features given by Scudder. In fact, were the 

 latter given generic significance it would be necessary to separate 

 gracilis and histrigata as one, litus as another, palmeri and dumicola 

 as another and valga as still another genus. 



Key to Males of the Species of Phwdrotettix. 



10 



A. Tegmina very slender, not elongate ovate or ovate. 



B. Dorsum of pronotum pale, immaculate. Distal portion of 

 abdomen not enlarged. (Fercula absent. Cerci moderately 

 elongate, slender, tapering to blunt apex. Supra-anal 

 plate elongate shield-shaped; truncate, obtuse-angulate 

 distad. Subgenital plate simple, small, scoop-shaped.) 



accola (Scudder). 



^ Scudder failed to note that the bases of the caudal tibiae were black in the 

 type of his parvidus. 



'•' The types, now before us, of Scudder's Pezotettix dumicolus and Rhabdotettix 

 concinnus show the certain synonymy of these names, the former of which has 

 prioritj'. At the time concinnus was described, Scudder referred dumicola to 

 the genus Melanoplus. 



1" This key is based on examination of the type of each species considered and 

 additional males of all except histrigata and litus, which species are known from 

 the unique type and allotj^pe. 



