72 



CALIFORNIA ACADEMY OF SCIENCES 



[Proc. 4th. Ser. 



are relatively heavy and flattened, much as in Mesochloa and 

 Cordillacris, though not showing the slightly greater flattening 

 proximad found in those genera. 



The pronotum, with caudal portion of disk produced mesad 

 and laterad and margin between concave, is distinctive. In 

 Mesochloa and Psoloessa alone do we find mere traces of con- 

 cavity of the lateral portions of the caudal margin of the pro- 

 notal disk. 



The inner spurs of the caudal tibiae are almost equal in 

 length, in this agreeing with Cordillacris, but not as long and 

 slender as in that genus. 



The ovipositor valves are very short, as in all the other 

 genera referred to above. 



Taking all into consideration, we believe that Esselenia 

 should be placed after Phlibostroma, though further study of 

 the proper order of the related genera may lead to its being 

 placed near Stiraplciira. The system generally in use for the 

 linear arrangement of the genera of the Acridinae is clearly un- 

 satisfactory, but can not be rectified until extensive studies of 

 the subfamily are made. 



Genotype. — Esselenia vanduzeei, new species. 



Figure 1. — Esselenia vanduzeei, new species. 

 Female. (X3) 



Dorsal view of type. 



