Bruner: South American Acridoidea. 99 



i .(Mm- /\ i.ni i i-i ron Rehn. 

 Zygoclislron Rehn, Knt. News, XVI, p. .-;'> (1905). 



rhe present v.ciuis is composed of medium- or slightly above medium- 

 -i/cd insects of modest coloration, which evidently live upon or near 

 the ground in or at the edges of forests. Two species have been 

 described in the past, and now a third is added. These insects are 

 found in southern Brazil and Paraguay. They may be separated by 

 1 he subjoined tabic 



Synopsis ok in 1: Simm n-.s 01. Zyc.oc i.istron. 

 .1. Tegmina of females, at least, much shorter than the abdomen. Pronotum 



strongly rugose trachystictum Rehn. 



.1.1. Tegmina of females fully developed, as long as, or longer than, the abdomen. 



Pronotum less strongly rugose. 



b. Smaller ($ 43 mm.). General color testaceo-ferruginous, not tinged with 



green or greenish, nor plainly banded with tiavous. . .modes turn sp. nov. 



bb. Larger (9 , 54 mm.). General color chrome-green, bay, and saffron; head, 



pronotum, and pleura conspicuously banded with flavous. 



superb um Rehn. 



138. Zygoclistron modestum sp. nov. 



As indicated by the preceding synoptic table, the present species is 

 readily separable from both of the other known species by its plain 

 and nearly uniform color; from trachystictum by the fully developed 

 tegmina and wings and the smoother pronotum; and from superbum 

 by its smaller size and the absence of flavous bands. In general 

 form and appearance similar to the figure of the latter (Proc. Acad. 

 Nat. Sci. Pliilad., 1907, p. 182, fig. 12). 



Size medium; head of moderate size, the occiput short, gently 

 bullate; vertex between the upper extremity of the eyes a little wider 

 than the shortest diameter of one of them, the fastigium separated 

 from the rest of the vertex by a plainly depressed transverse line, its 



isterior width nearly twice that of its length, the antero-lateral edges 

 slightly elevated, meeting at an obtuse angle, the middle widely and 

 shallowly sulcate. Frontal costa fairly prominent, it? upper end very 

 narrow, the sides strong and evenly divergent below, continuous to the 

 clypeus, deeply and widely sulcate throughout; lateral or facial 

 carinae also prominent, rather strongly divergent below. Eyes elon- 

 gate, subpyriform, a little longer than the anterior edge of the cheeks 

 below them. Antennae moderately robust, about as long as the head 

 and pronotum combined. The latter subcristate, transversely rugoso- 



