1920.] NATURAL SCIENCES OF PHILADELPHIA. 279 



third, a fine medio-longitiidinal sulcus impressed for some distance 

 caudad of the transverse sulcus: lateral lobes of the pronotum dis- 

 tinctly longitudinal; cephalic margin of lobes strongly oblique, 

 arcuato-truncate; ventro-cephalic angle hardly indicated; ventral 

 margin oblique truncate; ventro-caudal angle rounded obtuse, 

 caudal margin strongly arcuate; humeral sinus deep, well rounded 

 rectangulate. Tegmina elongate lanceolate, the greatest width 

 contained slightly more than nine times in the length, surpassing 

 the apex of the abdomen by more than twice the dorsal length of 

 the head: costal margin straight except for a regular arcuation in 

 the distal third to the suturad apex, which is rather well rounded: 

 stridulating field small, in its entirety not quite two-thirds as long 

 as the dorsum of the pronotum, free margin but moderately arcuate, 

 stridulating vein not more pronounced than the other veins of the 

 field. Wings equalling the tegmina. 



Prosternal spines very elongate, aciculate, parallel; sternal lobes 

 strongly compressed, those of mesosternum rounded rectangulate, 

 of metasternum arcuate laterad, with an extremely faint obtuse- 

 angulation caudad. Disto-dorsal abdominal segment with a broad, 

 relatively shallow, obtuse-angulate depressed area on the distal 

 half of the dorsal surface, this area deepest disto-mesad and its 

 proximal outline is rectangulate, the distal margin obtuse-angulate 

 emarginate, the supra-cereal angles moderately acute, cereal emar- 

 ginations relatively deep, broad, truncate at the bottom: sub- 

 genital plate reflexed, linguiform: cerci of medium length, moder- 

 ately robust, covered with shagreenous points which give rise to 

 short chaetiform and long piliform hairs; when seen from the dor- 

 sum the cerci are nearly straight, when seen from the side they are 

 moderately regularly arcuate, subequal in depth; apex obliquely 

 subtruncate, supplied with two spines, one large and cultriform, 

 directed dorsad, the other aciculate, directed toward the median 

 line and placed distad of the cultriform spine; subgenital plate 

 compressed, relatively short, distal margin narrowly fissato-emar- 

 ginate; styles articulate, short. 



Cephalic and median limbs relatively short, comparatively slender: 

 caudal femora elongate, slender, one-half as long as the tegmina; 

 ventro-external margin Avith two to five spines, ventro-internal 

 margin with two to three spines. Genicular lobes unarmed except 

 those of the caudal femora and the caudal one on the median femora. 



Allotype. — 9; Iga, River, State of Amazonas, Brazil. (Thayer 

 Expedition.) [Museum of Comparative Zoology.] 



