254 ORTHOPTERA. 



ARNILIA, Stal. 



Arnilia, Stal, Recens. Orthopt. i. pp. 42, 84 (1878) ; Syst. Arid. i. p. 40 (1878). 

 Stenacris, Walker, Cat. Dermapt. Salt. Brit. Mus. p. 651 (1870) (in part.). 



The representatives of the genus Arnilia are confined to tropical and subtropical 

 America, where they occur among the rank grasses and sedges growing in and about 

 swamps and along the margins of streams. This being true, it is quite probable that 

 the actual number of species is comparatively large. At present only about a dozen 

 ate known, including those now described or characterized in the subjoined synoptic 

 table. The species cylindrodes and vitreipennis may both be considered the types of 

 the genus, because both were represented when the generic diagnosis was drawn up 

 by Stal, as may be seen by an examination of pages 42 and 85 of his * Kecensio 

 Orthopterorum,' i. 



Synoptic Table of the Species of Arnilia. 



A. Last ventral segment of male abdomen plain, unadorned at sides 

 by dentiform processes or at the apex by flattened decurved 

 lobes. 

 b. Larger ( $ , length 36-44 mm.). 



c. Antennae decidedly ensiform. Hind tibiae provided with 

 9-10 spines in the outer row. Tegmina acuminate. Wings 

 rather strongly infuscated, or at least with obscure veins. 



(South-western Brazil.) [stall, sp. n.] 



cc. Antennae only faintly ensiform or subensiform. Hind tibiae 

 7-spined externally. Tegmina subacuminate. Wings not 

 infuscate nor dark-veined. 

 d. Hind tibiae together with the tarsi wholly pale coral-red. 



The abdomen above testaceous [coccineipes, Bruner.] 



dd. Hind tibiae with a large green space towards the base. 



The abdomen above blood-red 1. viridis, Serv. 



bb. Smaller ( $ , length 24-35 mm.). 



c. Relatively robust species. Fastigium of the vertex obtuse or 

 at most a right-angle. Sides of the pronotum and pleura 

 without a piceous band. 

 d. Prosternal spine moderately robust, equal, the apex blunt. 



(Rio de Janeiro and Eastern Brazil.) [cylindrodes, Stal.] 



dd. Prosternal spine inflated at apex, gently retrorse. (Co- 

 rumba, Brazil.) [interior, sp. n.] 



cc. Relatively slender species. Fastigium o£ the vertex acumi- 

 nate. Sides of the pronotum and pleura adorned with a 

 piceous line above the pale one. (Paraguay and S. Brazil.) [gracilis, G.-Tos.] 



