254 PROCEEDINGS OF THE NATIONAL MUSEUM vol. io« 



25. Both sexes completely apterous Arachnopsis Saussure 



Males with greatly reduced elytra, without perceptible veins ; female apterous . 26 



26. Legs and palpi short Laranda Walker 



Legs and palpi very long, posterior femora with filiform apical part ... 27 



27. Legs moderately elongate; elytra of male triangular, thick, feebly distant on 



the median line Eidmanacris, new name » 



Legs extremely long; elytra of male thin, overlapping, truncated at apex. 



Phalangopsis Serville 



28. Anterior tibiae perforated on both faces Paragryllus Guerin 



Anterior tibiae perforated on one face only 29 



29. Anterior tibiae perforated on the internal face 30 



Anterior tibiae perforated on the external face . . . Ectecous Saussure 



30. Elytra of male short, triangular, without well defined mirror; those of the 



female reduced to lobiform, lateral pads Uvaroviella Chopard 



Elytra of the male with well defined mirror 31 



31. Mirror oval, divided by numerous veins; female apterous . . AclaHebard* 

 Mirror vaguely triangular, divided near the apex by one or two irregular 



veins; elytra present in the female Aclodes Hebard 



32. Elytra of male very short, truncated, or absent . . . Paracophus Chopard 

 Elytra of male moderately short with normal venation 33 



33. Superior apical spur of posterior tibiae longer than the median on both sides; 



anterior tibiae perforated on the internal face .... Endecous Saussure 

 Superior apical spur of posterior tibiae shorter than the median 34 



34. Anterior tibiae perforated on both faces; elytra of male rather short, rounded; 



mirror with two dividing veins Amphiacusta Saussure 



Anterior tibiae perforated on the external face only; elytra of male coriaceous; 

 mirror divided by several veins Hemicoplius Saussure 



Genus Prosthacusta Saussure, 1874 

 Prosthacusta ampUpennis, new species 



Figures l,c, 3,d 



Holgtype: Male; Pucallpa, Rio Ucuyali, Peru, Sept. 16, 1947, 

 Schunke (USNM 62065). 



Male: Close to P. circumcincta Saussure; coloration rather uniform 

 light brown. Head rather small, as wide as pronotum, uniformly 

 brownish, almost glabrous; vertex strongly sloping; frontal rostrum as 

 wide as first antennal joint. Face long, yellowish, smooth. Antennae 

 and palpi yellowish; maxillary palpi rather long, the three last joints 

 equal in length, the last one feebly enlarged, obliquely truncated at 

 apex. 



Pronotum as long as wide, with straight anterior and posterior 

 margins; disk strongly convex, brown, smooth, glabrous; lateral lobes 

 long, with inferior margin straight, rounded angles. Abdomen dark 

 brown above, yellomsh beneath; subgenital plate long, truncated at 

 apex; epiproct almost twice as wide as long, feebly truncated at apex, 



» For Eidmanitlla Chopard (Aug. 1938), preoccupied by Eidmanidla Keler (March 1938). 

 « It seems that this genus may represent the male sex of Heterogryllus Saussure; In that case, the laet 

 name would have priority. 



