186 PROCEEDINGS OF THE ACADEMY OF [May, 



the male. The latter feature consists of the pale callose area in 

 jugatus being present only on the pleura, while in apterus the ventral 

 portion of the lateral lobes is of similar character. 



From debilis the new species can be readily separated by its more 

 finely rugoso-punctate surface, much more declivent fastigium, 

 more prominent eyes, less apparent median carina of the pronotum, 

 more elongate auditory tympanum, less strongly carinate dorsal 

 line of the abdomen, stouter female cerci, the more acute extremity 

 of the prosternal process, the less decidedly serrate character of 

 the ventral margin of the caudal femora and the reddish brown 

 coloration. As the male of debilis is unknown we cannot compare 

 that sex. Bruner's nudus from Santarem, may be closely related, 

 but such information as we are able to secure from his very incom- 

 plete and not at all convincing remarks on that species seems to 

 point to their being different. 



Type: cf; Igarape-assu, State of Para, Brazil. (H. S. Parish.) 

 [Acad. Nat. Sci Phila., Type no. 5291.] 



Size large (for the genus); form robust; surface of head largely, of 

 dorsal thoracic and single proximal abdominal segments strongly, 

 ruguloso-punctate, other proximal abdominal segments faintly sculp- 

 tured dorsad. Head with the occiput not elevated dorsad of the 

 pronotum, distinctly declivent to and including the vertex and fasti- 

 gium; interocular width of the vertex very narrow, equal to less than 

 one-half of the interantennal width of the costa, finely sulcate; fasti- 

 gium rather short, broader than long, cephaKc bounding margin of 

 the impresso-punctate surface rectangulate, with a fine median con- 

 tinuation of the sulcus of the vertex: frontal costa faintly produced 

 between the antennal bases, fastigio-facial angle obtuse, facial line 

 considerably retreating, dorso-ocellar section of the costa subequal in 

 width, broad, wider than the proximal antennal joint, non-sulcate, 

 thickly punctate, surface impressed about ocellus, the margins of the 

 costa compressed immediately ventrad of the same, briefly sulcate, 

 thence costa is obsolete: eyes quite prominent, ovate in basal outline, 

 the length twice that of the infra-ocular portion of the gense : antennse 

 filiform, elongate, in length twice as long as the head and pronotum 

 together. Pronotum sub-cylindrical, moderately expanding caudad, 

 the greatest caudal width of the disk subequal to the dorsal length of 

 the same, in transverse section faintly tectate: dorsal margin of- 

 pronotal disk arcuate produced, faintly and broadly emarginate 

 mesad; caudal margin subtruncate with a very broad and shallow 

 median emargination; median carina faintly and rather irregularly 



