60 PROCEEDINGS OF THE ACADEMY OF [Maich, 



,neo-mexicana\ Form slender, elongate. Lateral fove- 



Group B I alacris > olae weakly indicated. Antennae 



' intertexta J very heavy. Pronotum elongate. 



Lateral carinae of pronotum distinct 

 or incompletely indicated {intertexta) , 

 faintly if at all divergent caudad. 

 Supplementary carinae on lateral 

 lobes of pronotum distinctly (alacris) 

 or weakly {neo-mexicana and inter- 

 texta) indicated. Caudal limbs elong- 

 ate, slender. 



/-I p jhivittata \ Form less slender than in Group B, 



^ [maculipennisl more attenuate than in Group A. 



Lateral foveolae indicated to a greater 

 (macuUpennis) or lesser (bivittata) de- 

 gree of completeness. Antennae 

 heavy. Pronotum short. No lat- 

 eral carinae on pronotum. No sup- 

 plementary carinae on lateral lobes of 

 pronotum. Caudal limbs relatively 

 robust. 



We feel quite confident that Groups A and B are the more primi- 

 tive ones, but which of these two is closer to the ancestral type 

 is difficult to say. In some ways texana appears the more general- 

 ized, in others alacris and neo-mexicana, with intertexta clearly 

 a more advanced type. We feel, however, that, as texana repre- 

 sents a divergence from the type species {neo-mexicana) in anti- 

 thetical characters from Group C, a clearer presentation of the 

 interspecific relationship is shown by arranging the species as 

 done herein. 



Distribution of the Genus. — From southern New Jersey (inter- 

 texta), central Illinois (neo-rnexicana and macuUpennis macclungi), 

 Iowa (neo-mexicana, bivittata and maculipennis macclungi) , Missouri 

 River region of North Dakota (neo-mexicana), and eastern Mon- 

 tana (Forsyth — maculipennis maccluiigi) ; south to the Florida Keys 

 (intertexta), the Gulf Coast (bivittata, alacris and maculipennis 

 maculipennis), southern Texas (Mission and Lyford — maculipennis 

 maculipennis), central Coahuila [Monclova] and northern Durango 

 [Lerdo), Mexico (texana), and southern Arizona (Huachuca and 

 Baboquivari Mountains — texana, neo-mexicana and maculipennis 

 maculipennis); from the eastern coast of the United States west 

 to northern Utah (Salt Lake City — maculipennis macclungi), south- 

 ern Nevada (Rioville — maculipennis maculipennis), and central 



