52 



Graea monstrosa n. sj). 



In structure very similar to Graea horrida of Philippi but 

 somewhat broader and more rugose, unicolorous, varying 

 from a dull testaceous brown to dark wood brown, in some 

 specimens greenish yellow. Some of the males have the 

 posterior portion of the disk of pronotum more or less 

 swollen and of a lighter color, otherwise as indicated above, 

 uniform throughout. The tubercles on outer face of hind 

 femora five in number instead of six as in G. horrida. 



Length: of body, d^ 28 mm, 9 34-36 mm; of j^ronotum, 

 c? 8 mm, 9 9.5 mm; width of pronotum in widest place, 6' 

 9 mm, ? 14 mm; of hind femora, d 11.5 mm, ? 13 mm; of 

 antennae, c? 10 mm, 9 12 mm. 



This insect is found in moderate numbers from Bahia 

 Blanca at the south to Cordoba in the north, being confined 

 chiefiy to uplands where it occurs on sandy soil among the 

 short scattered vegetation. 



From collections of H. Stempelmann and F . Schulz. 



Fig. 20. — Gra a monsti'osa, female. 



SUB-FAMILY ACRIDIINAE. 



This is by far the most extensive sub-family of locusts 

 represented in the region covered by the j3resent paper, and 

 contains, with but two or three exceptions, all of the de- 

 structive species. The following rather long table for the 

 separation of the genera to which these insects belong will 

 be of some value to the reader in sejDarating the many forms 

 that occur in any particular region. In genera where more 

 than one species occur there will also be found tables for 

 the separation of the different sj^ecies. Those which have 



