1913.1 NATURAL SCIENCES OF PHILADELPHIA. 273 



A CONTRIBUTION TO THE KNOWLEDGE OF THE ORTHOPTERA OF 

 ARGENTINA. 



BY JAMES A. G. REHN, 



The present paper is based entirely on collections made by Mr. 

 P. Jorgensen, of Buenos Aires. These collections were sent either 

 direct to us for study or through Mr. Esben Petersen, of Silkeborg, 

 Denmark, to whose interest we are obligated for much of the material 

 treated in the paper. In addition to thanking these gentlemen for 

 the opportunity to study the present collections, we also wish, on 

 behalf of the Academy, to thank Mr. Jorgensen for the very important 

 additions received from the collection, by far the greater portion of 

 which, including all the types and unique specimens, remain in the 

 Academy series. 



The entire series, collected over the greater portion of northern 

 and north-central Argentina, comprises ten hundred and twenty 

 specimens, representing one hundred and sixty -two species, of which 

 three genera and twenty species are new to science. 



The general regions represented in the collections are: 



First. Territory of the Misiones. The extreme northeastern 

 extension of Argentina extending between the Parana and Uruguay 

 Rivers, which respectively separate it from Paraguay and Brazil. 

 In consequence of its f>osition it has a far greater proportion of tropical 

 types than any other portion or portions of Argentina. 



Second. Province of Corrientes. Southwest of the Misiones and 

 between the same rivers, but of a less tropical character. 



Third. Province of Jujuy. The extreme northwestern province, 

 forming part of the Bolivian boundary. This is a region charac- 

 terized by a number of types of Orthoptera peculiar to it or shared 

 with Bolivia or the province of Salta to the south and east. 



Fourth. Province of Salta. This province is next south of Jujuy, 

 which it also bounds on the east, the latter portion forming part of 

 the Chaco region. 



Fifth. Province of Tucuman, South of Salta and at the east base 

 of the Andean uplift, part of which is within the province. 



Sixth. Provinces of San Juan and Mendoza. These are in the 

 •west-central part of the country, forming a considerable part of the 

 Chilean frontier and including conditions from the plains to the 



