36 PROCEEDINGS OF THE ACADEMY OF [Feb., 



olive, except for a pregeniciilar annuliis of clear green; caudal tibise 

 bice green, the genicular section blackish and the distal portion slightly 

 suffused with brownish, spines and spurs tipped with black. 



Measurements. 



Length of body, 26 mm. 



Length of pronotum, 5 " 



Length of tegmen, 19 " 



Length of caudal femur, 16.3 " 



A paratypic series of nine males have also been examined, the dates 

 being as follows: December 21, 1904; January 26, February 15, March 

 7, 18 and 21, 1905. This series is rather uniform in size, two females, 

 however, being appreciably smaller than the others. In color one 

 specimen has the green more glaucous, while several others show a 

 tendency in the same direction. One specimen has the caudal femora, 

 the lateral lobes and the face suffused with orange vermilion. The 

 intensity of the longitudinal bars appears to vary very little; on the 

 tegmina, however, some specimens are more strongly colored than 

 others. 



ISONYX n. gen.20 



This genus probably is closer related to Borellia Rehn ^^ than to 

 Staurorhectus, and may possibly be considered a distinct and separate 

 type with no close relationship to either the above mentioned genera. 

 The characters are so contradictory and the facies so different that 

 the author does not feel jvistified in making detailed comparisons, but 

 prefers to present the rather striking features of the form in the general 

 description. It might be added that this position is assigned to 

 Isonyx after studying all the South American Gomphoceri, both genera 

 and species. 



Isonyx paraguayensis n. sp. 



Types: d^ and ?. Sapucay, Paraguay. February 12 ( 9 ) and 

 27 (cJ^), 1905. (Foster; Nos. 24 and 165.) Hebard Collection. 



Size rather small; form moderately compressed and slender; surface 

 subsericeous. Head slightly (cJ^) or considerably (9) shorter than 

 the pronotum, the occiput very slightly elevated and rounded; fasti- 

 gium subrectangulate in the male, obtuse-angulate in the female, very 

 much shorter than the width at the cephalic angle of the eyes, margins 



20 I(Tof , equal; owx, claw. 



-1 Proceedings of the U. S. iSational Museum, XXX p. 379. 



