10 PROCEEDINGS OF THE ACADEMY OF [Feb;, 



STUDIES IN SOUTH AND CENTEAL AMERICAN ACRIDINiE (ORTHOPTERA), 

 WITH THE DESCRIPTIONS OF A NEW GENUS AND SIX NEW SPECIES. 



BY JAMES A. G. REHN. 



The subfamily treated in the following pages is usually termed the 

 Truxalinse, but the resurrection of the Old World Linnsean genus 

 Acrida necessitates the use of the name Acridinae. 



Of this subfamily by far the majority of the South and Central 

 American genera have been studied in this connection and numerous 

 opinions and conclusions regarding their relationship are given in the 

 following pages, while several genera, or subgenera, have been con- 

 sidered untenable and one new one proposed. The consideration of 

 several wrongly identified or overlooked species caused a shifting of 

 generic names, which necessitated in one case a new generic name. 



Twenty-two genera have been considered in more or less detail, and 

 sixty-three species, of which six are new, have been examined. The 

 material examined numbered six hundred and twenty specimens, of 

 which two hundred and sixty-seven were from the Academy Collection, 

 three hundred and twenty-eight from the Hebard Collection, and 

 twenty-five from various sources. 



I wish to express my thanks to Mr. Hebard for the privilege of 

 examining the material from his collection. 



HYALOPTERYGES. 

 HYALOPTERYX Charpentier. 

 1845. Hyalopieryx Charpentier, Orthopt. Descr. et Depict., tab. 46. 

 Type. — H. rufipennis Charpentier. 



From its closest allies Hyalopteryx can be separated as follows: 

 from Radinotatum by the presence of well developed tegmina and wings, 

 the caudal expansion of the pronotum and the much shorter rostrum 

 and less produced head; from Achurum by the more robust form, 

 the caudal expansion of the pronotum (more or less pronounced ac- 

 cording to the sex), the much broader tegmina and wings as well as the 

 shorter, blunter rostrum and less produced head ; from Eutryxalis in 

 the longer, slender limbs, the somewhat broader tegmina, the shorter 



