58 GUIDE TO ORTHOPTERA 



Pacific coast; it ranges over the desert region eastward to the 

 Rocky Mts. ; a larger number of species occur south of our 

 border, 



Rhaphidophorini. 



Two of the four groups into which this tribe may be divided 

 occur in North America, the other two belonging exclusively to 

 the Old World. One of our groups is peculiar to the United 

 States, and the other much more highly developed here than else- 

 where, though shared with South America and the Old World. 



Groups of Rhaphidophorini. 



a 1 . Hind tibiae supplied above and below with spines of one 

 grade only, on both outer and inner margins. Tropidischiae. 



a 2 . Hind tibiae furnished above with spines of two grades, 

 longer being interspersed with shorter spines (obscure in Gam- 

 marotettix) ; beneath nearly or quite unarmed, such spines as are 

 present occurring on the middle line only. . Ceuthophili. 



Tropidischiae. 



Its only known genus, Tropidischia Scudder, is monotypic and 

 is found in California. 



Ceuthophili. 



This group, as developed in the United States, contains six of 

 the nine genera known to belong to it, and all of these are peculiar 

 to the United States, excepting as they may extend southward 

 into Mexico. It is the most representative group of temperate 

 North American Locustidae. 



Genera of Ceuthophili. 



a 1 . Last palpal joint cleft apically on the under side. Descend- 

 ing lobes of the mesonotum but little longer than those of the 

 pronotum ; sides of fore and middle coxae externally laminate, the 

 lamination elevated to a denticle or compressed spine either 



