WALSH — DESCRIPTIONS OF N. AM. HYMEXOPTERA. 97 



scarcely incrassated, cylindrical, and truncate a little obliquely 

 from above downwards, the rest all short ; joint 2 not much shorter 

 than the ist joint of the flagellum. Thorax with the parapsidal 

 grooves obsolete. Scutel triangular, flattish, elevated. Metatho- 

 rax with the carinate areas mostly developed. Abdomen sessile, 

 elongate suboblong, compressed at tip ; joint i unusually long, its 

 sides but slightly converging in front. Joints i and 2 strongly 

 sculptured and opaque ; the rest glabrous and polished. Venter 



excavated. Ovipositor ? Legs robust and short ; coxae and 



femora incrassated, especially in the hind legs. Spurs normal. 

 Tarsal claws simple, and, as well as the pulvillus, long and slen- 

 der. Wings moderate. Radial area and stigma very short. Areo- 

 let large, pentagonal. Both recurrent veins but slightly curved. 

 Veins at the tip of the wing subobsolete, except those of the radial 

 area. Bullae indistinct but apparently 4, A, B, CD, andE ; A and 

 B on the outer side of the areolet (as in Orthocentrus^ Grav.), C 

 and D confluent or separated only by an indistinct dot, andE rather 

 nearer to the angle of its vein than to the areolet. 



Differs from Exochus^ Grav., by its large pentagonal areolet, by 

 its long tarsal claws and pulvillus, and the great length and coarse 

 sculpture of its first two abdominal joints ; from Periope, Haliday, 

 by its sessile abdomen, by its spurs i, 2, 2 (not i, 2, i), by its sim- 

 ple claws, and by its large pentagonal areolet ; from Orthocentrus, 

 Grav., it is separated at once by its simple claws ; and from Polyr- 

 habdus^ n. g., by its areolet not being obsolete. In the compressed 

 tip of the abdomen it resembles Periope^ Hal. 



Exochiscas pusillus, n. sp. — c??— Black. Head subopaque, with mi- 

 nute, rather sparse punctures ; vertex polished. Face projecting beyond 

 the eyes by a space equal to their shorter diameter. Face brown; lower 

 part of the face, clypeus, cheeks, mandibles except their teeth, and palpi, 

 all brownish-yellow. Antennae yellowish-brown, very robust, a little con- 

 volute at tip, half as long as the body. Joint i, 2^ times as long as wide, 

 scarcely more robust than the flagellum; joint 2 square; ist joint of the 

 flagellum longer by i than wide ; the rest slowly shorter and shorter. 

 Thorax subpolished, with minute, rather sparse punctures; the entire 

 pleura and the metanotum polished and glabrous. Metathorax with the 

 carinate areas complete, save that the cross-carinae of the lateral areas are 

 absent, and the basal is confluent with the central area; the two dorsal 

 carinae converging on their basal \, thence straight and equidistant, the 

 space between them with transverse rugae; exterior tip of the lateral area 

 prolonged in a minute, robust, blunt thorn. Tegulae brownish-yellow. 

 Abdamen with joints i and 2, except their extreme tips, opaque and 



iii — 7 [May 33, 1873.] 



