REHN AND HEBARD 239 



Tegmina ^. . -^ Spines of ventro- 



Macropterous Brachypterous Ovipositor external margins 



of caudal femora 



resinum** cf "19" ? none (by infer- 



9 ence). 



aberrans* _ cf "subrectus." "none." 



9 "17-20.5" "8.5-9" 



doryphorum** (^ "rectus." "none." 



Q ... "0.3" "11" 



In the species marked with an asterisk not sufficient material 

 is known to give the probable extremes of the above diinensions, 

 those marked with two asterisks are known from the unique 

 types. 



In the known females of the species here considered, the ovi- 

 positors of all range from scarcely arcuate to straight excepting 

 in C. borelli and C. truncatus, and in C. spinosus the arcuation is 

 nearly as pronounced as in those species, accompanied by a dis- 

 tinctive shape. 



Comparison with an analogous chart -^ in the authors' first 

 paper on the present genus shows, that in tropical America fewer 

 species are known to develop both macropterous and brachypter- 

 ous conditions than in the United States. This is doubtless 

 partially due to the fact that our knowledge of the tropical species 

 is in almost every case more limited. In future time, experi- 

 mentation and study will doubtless bring to light many interest- 

 ing factors governing the development and relative abundance 

 of the macropterous and brachypterous condition in the species 

 of this genus. 



Subgenus Opeastylus^^ new subgenus 



The subgenus includes two species, both from temperate and 

 subtropical South America. 



Type of Subgenus — Conocephalus I'itticoUis [Locusta vitticoUis] 

 (Blanchard). 



Subgeneric Description. — Prosternum bispinose. Subgcnital 

 plate of male very strongly and sharply produced disto-laterad 

 in sharp straight spikes which are weakly divergent, on the ven- 

 tral surfaces of these productions are situated awl-like styles, 



28 Trans. Am. Ent. Soc, xli, p. 167, (1915). 



25 From 67r£as=awl and (rTOXoj=a pillar (the stj'les), in allusion to the 

 awl-like styles of the male subgenital plate in the species of the subgenus. 



TRANS. AM. ENT. SOC, XLI. 



