56 OETHOPTEEA. 



1. Silvitettix communis, sp. n. 



Varying in colour from dark wood-brown to almost black on the head, pronotum, pleura, and sides of the 

 abdomen in the male, but in the female frequently varied on the top of the head, pronotum, dorsal edges 

 of the tegmina, and dorsum of the abdomen with ferruginous, testaceous, or cinereous, paler below. 

 In some females the entire insect becomes much lighter-coloured. About half of the individuals 

 of this sex have the upper edges of the lateral lobes of the pronotum black, but this longitudinal 

 dark streak is in no way regulated by the lateral carinae, since they are crossed both in front and 

 behind the middle, passing forward on the head as far as the eyes and backward to the lower half of the 

 tegmina. Hind femora in the female with the inner and outer faces, as well as the apex, obscure, the 

 upper edge and sometimes the lower sulcus paler, often of a reddish hue ; in the male the apex alone 

 black, the remainder varying in colour from testaceous to brown, with a tinge of red shining through 

 from inside. Tibiae infuscated. Antennae pale basally, infuscated apically. Labial and maxillary palpi 

 pale yellow or testaceous. 



Length of body, tf 13, $ 23; of antennae, <3 11-13, $ 8; of pronotum, S 3, $ 4"75; of tegmina, " tf 5-6, 

 5 5 ; of hind femora, S 10, $ 13 millim. 



Flab. Costa Rica, Monte Redondo and Juan Vinas (L. JBruner, M. A. Carriker, Jr., 

 M. Cary, and C. F. Undenvood), Pozo Azul (M. A. Carriker, Jr.). 



This short-winged locust is very common in small openings and about the edges of 

 heavy woods, where it is to be found among the fallen leaves and rank vegetation. 

 There are evidently two or more generations of it during the year, since large numbers 

 of the half-grown nymphs occurred along with the mature insects taken late in 

 February and throughout March. It seems to be rather general in its distribution, as 

 the localities from which specimens were received range from the eastern slope nearly 

 to the Pacific, and irom near the sea-level to almost or quite 4500 feet above. 



OCHROTETTIX, gen. nov. 



Head with the occiput quite long ; the vertex, which is a little wider than the shortest diameter of the eyes 

 and projects forward about the same distance, tumid and provided with a well-defined median carina, 

 this being continued over the back of the head to the front edge of the pronotum, the sides rounded as in 

 Mermiria, without lateral foveolae ; face strongly oblique, the frontal costa quite prominent between the 

 antennae, narrow, with well-defined bounding carinae, continuous to the clypeus, a trifle widened below, 

 sulcate throughout. Antennae with the basal joints much flattened, decidedly ensiform in $ , scarcely so 

 in S , nearly ( $ ) or quite ( <$ ) as long as the hind femora. Eyes of medium size, elongate-pyriform, 

 oblique. Pronotum almost cylindrical, about as wide in front as behind, the lateral carinae wanting or 

 occupying the place of supplemental discal carinae, which latter are nearly parallel and as distinct as the 

 median, and continue upon the occiput as faint parallel carinae to the eyes; front and hind edges of the 

 disc broadly rounded or subtruncate, the lower edges of the sides nearly straight ; transverse sulci very 

 obscure, the last decidedly behind the middle. Tegmina abbreviate in both sexes, the apex rounded, in 

 the female the dorsal edges scarcely touching, but overlapping in the male. Hind femora surpassing the 

 tip of the abdomen in both sexes, only moderately robust. Hind tibiae with 12 or 13 spines in the outer 

 row, the apical spurs subequal. Sexes very unequal in size. 



1. Ochrotettix salillUS, sp. n. (Tab. I. figg. 4, 4 a, 6 ; 5, 5 a, 2 .) 



The type of the genus, the only species known, has the fastigium of the vertex provided at the sides and front 

 with a slightly raised blunt carina ; the face when seen from the side a little hollowed just above the 

 ocellus. Tegmina in the female reaching to about the middle of the second abdominal segment, those of 

 the male a trifle more than half as long as the abdomen. The general colour, apart from a very faintly 



