312 PROCEEDINGS OF THE ACADEMY OF [May, 



The measurements of the present specimens are as follows : 



Male. Female. Female. Imm. Female. 

 La Paz. La Paz. La Paz. Alto Pencosa. 

 mm. mm. mm. mm. 



Length of body 60. 101. 93. 67. 



Length of head 10.8 19. 15.5 12.2 



Length of rostrum 5.8 11.8 8.2 6.2 



Length of pronotum 12.5 20.7 19.5 13.2 



Length of tegmen 4. 3.5 2. 



Length of cephalic femur 10.5 14.3 13. 9. 



Length of caudalfemur 20.5 32.5 30. 19.2 



As the male has not been previously reported, the differential 

 characters of that sex may be of service.^^ 



Size rather small; form very elongate. Head very similar to that 

 of the female, but the eyes are more prominent and the depth of the 

 head caudad of the eyes is subequal for a greater distance and not 

 regularly increasing in depth as in the female. Pronotum with the 

 greatest (supra-coxal) width contained about five times in the 

 length of the same; cephalic margin with two low nodes instead of 

 high spiniform tubercles; caudal margin unarmed; no lateral carinse 

 present as in the other sex; the general form of the pronotum more 

 subequal in width and not gradually enlarging caudad as in the 

 female. No trace of tegmina and wings. Narrowest portions of 

 the mesonotum and metanotum subequal in width to the pronotum ; 

 mesonotum with no spines on the margin. Abdomen not multi- 

 carinate, a single median carina indicated; supra-anal plate lanceo- 

 late, the apex not rounded, surface sUghtly excavate, not sulcate; 

 cerci simple, tapering, very short, blunt; subgenital plate greatly 

 produced, rostrate, subdeplanate, dorsal surface sulcate, apical 

 margin strongly divided, hardly carinate ventrad. Limbs slenderer 

 than in the female; caudal femora reaching to the caudal margin of 

 the fifth abdominal segment. 



Subfamily ACRIDIN^. 

 *Hyalopteryx rufipennis Charpentier. 



1845. Hijalopteryx rufipennis Charpentier, Orthopt. Desc. et Depict., 

 tab. 46. [Brazil.] 



Misiones. January 1, 1910; January 3, 1909; December 10-12, 

 1909; December 12, 1910. (No. 13.) Nine males, two females. 

 These specimens are quite uniform in color and when compared 



" The data here given are from the La Paz male measm-ed above, this being 

 the allotype of the species. 



