176 rROCEEDINGS OF THE NATIONAL MUSEUM. vol.53. 



NYSSON (HYPONYSSOK) RAL'I, new species. 



In both Cresson's and Fox's keys this species goes to hicolor 

 Cresson, but the sculpture of the prothorax easily separates it from 

 that species. 



Female. — Length 4 mm. Clypeus convex, the apical margin de- 

 pressed, rounded, the apical part of the convex portion polished, 

 the basal part with large and small punctures; front opaque with 

 close, fine punctures; vertex and posterior orbits more sparsely 

 punctured; postocellar line distinctly shorter than the ocellocular 

 line ; the interocellar area not tuberculate ; antennae short, stout, not 

 extending beyond the tegulae, the second and third joints subequal in 

 length, the third distinctly longer than the fourth; pronotum 

 rounded, opaque, finely punctured; mesoscutum opaque, tlie punc- 

 tures somewhat larger than those of the prothorax; scutellum not 

 margined, punctured like the scutum; metanotum flat, propodeal 

 inclosure longitudinally reticulate; angle of piopodeum with a 

 feeble, sharp spine; posterior aspect of propodeum granular, 

 margined laterally and with two feeble longitudinal carinae medi- 

 anly; sides of propodeum granular; legs rather stout, the longer 

 calcarium of the hind tibiae half as long as the basitarsis; hind 

 basitarsis curved near base ; abdomen subopaque with fine close punc- 

 tures; p3^gidium well defined and rounded apically, fully twice as 

 long as basal width. Black; mandibles piceous; tubercules and 

 small lateral spots on apical margins of first three tergites whitish, 

 first and side of second abdominal segments rufous; bodj'' clothed 

 with dense appressed silvery pile. Wings dusky hyaline, venation 

 black. Third intercubitus wanting; nervellus fully three times its 

 length before cubitella. 



Type-locality. — St. Louis, Missouri. Described from one female 

 collected by Phil Rau, for whom the species is named, and sent under 

 his number 2479. 



Type.— Cat No. 21406, U.S.N.M. 



Although most authors have suppressed Cresson's name Hypo- 

 nysson the finding of this second species would seem to indicate that 

 it can conveniently be used at least as a subgenus. 



