Bruner: South American Acridoidea. 07 



acuminate; hind tibiae heavy, short, six-spined on outside and rath< i 

 strongly hirsute; hind tarsi with the second joint aboul one-half as 

 long as the first. Las1 ventral segment of male abdomen short. 

 pinched from sides so as to form a short longitudinal ridge; supra- 

 anal plate with the sides nearly parallel on basal half, then suddenly 

 contracted to aboul one half the width and completed as a triangular 

 projection the tenter of which is provided with a median carina, which 

 separates and forms a loop towards the base of the plate, each side ol 

 disk provided with three or four dark tubercles; anal cerci heavy, two 

 and one-half times as long as wide and twisted on outer half. Pro- 

 sternal spine very short and broad at base, but with the apex terminat- 

 ing in a small short tubercle. Entire insect sparsely hirsute, save on 

 lower side of abdomen apically, where the hairs form two decided tufts. 



General color pale olive-green, paler below. Hind femora and 

 tibiae much darker green, the sides of genae and base of tibiae blood-red, 

 on the latter followed by a dusky patch and then by a narrow pale 

 annulus; tarsi testaceous. Tegmina brownish-olive with a narrow, 

 but well defined, median longitudinal testaceous vitta on each, running 

 from the base to the apex. Basal joints of antennae pale, beyond 

 bright red. 



Length of body, cf - 15.5 mm., of antennae, 9.5 mm., of pronotum, 4 

 mm., of tegmina, 11.5 mm., of hind femora, 10.5 mm. 



Habitat. — A single male collected during early April at Demerara, 

 British Guiana, by R. J. Crew. (Coll. L. Bruner.) 



Genus Hisychius Stal. 



Hisychius Stal, Bihang. Svensk. Akad. Handl., V, no. 4, pp. 44, 89 (1878). 



The representatives of the present genus of apterous locusts are 



confined to tropical America and mostly to the northern half of South 



America. Three species have thus far been characterized, and now a 



fourth i> added. These may be separated by the annexed synoptical 



key. 



Synopsis of the Species of Hisychius. 



.1. Antennae linear. Fastigium of the vertex declivant. 



b. Knees of hind femora concolorous. Spines of hind tibiae entirely black. 

 c. Larger ( 9 , 45 mm. long). Lower outer carina of discoidal area of hind 

 femora adorned with alternating conspicuous black teeth, or spines. 



[Peru.] nigrispinus Stal. 



cc. Smaller ( 9 ■ 33 mm. long). Lower outer carina of discoidal area adorned 

 with small inconspicuous teeth. [Para, Brazil.], .brasiliensis sp. nov. 



