No. 2312. NEW NORTH AMERICAN HYMENOPTERA—ROHWER. 229 



Male. — Length 6 mm. Clypeus gently convex, the anterior margin 

 with two distinct teeth medianly which are separated by an arcuate 

 emargination ; base of the clypeus and the face below the carina finely 

 aciculate over a finely granular surface; face strongly elevated below 

 the antennae, the vertical margin of the elevation bounded by a sharp 

 transverse carina which is notched dorsally at the middle and does not 

 reach the inner eye margin; seen from in front this elevation has two 

 strong median carinae which converge and unite a short distance 

 before the transverse carina which they join at the median notch; 

 hes e carinae also converge and unite a short distance above the 

 antennae and extend dorsally as a strong carina to the anterior ocel- 

 lus; front, vertex and posterior orbits shining with widely separated 

 small punctures; ocelli in a low triangle, the postocellar line subequal 

 with the ocellocular line; antennae short, stout, slightly thickening 

 apically, third joint slightly longer than fourth and twice as long as 

 pedicellum; pronotum with a sharp transverse carina anteriorly but 

 not dentate laterally ; scutum and scutellum shining, with a few widely 

 separated small punctures; suture between scutum and scutellum 

 strongly foveolate; metanotum punctured like the scutellum; pro- 

 podeum with the basal inclosure with strong rugae which become 

 transverse posteriorly; dorsally the rest of the propodeum is polished, 

 impunctate; posterior aspect of the propodeum finely transversely 

 rugulose on a granidar surface on each side of the deep median chan- 

 nel; meso and metapleurae polished practically without sculpture; 

 the oblique suture on mesepisternum foveolate; sides of propodeum 

 sculptured like the posterior aspect; legs rather short; longer calcaria 

 of hind tibiae curved and subequal in length with the hind basitarsis; 

 petiole trisulcate dorsally, subequal in length with the rest of the first 

 tergite, shorter than the hind femora; abdomen shming, impunctate; 

 first and third abcissae of radius subequal fully three times as long as 

 the second abcissa; first recurrent closer to the base of the second 

 cubital than the second recurrent is to the base of the third cubital; 

 hind wings normal. Black; rather sparsely clothed with silvery hair; 

 wings hyaline, iridescent; venation very dark brown. 



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

 lected July 6, 1918, by Phil Rau and forwarded under his number 

 3584. 



Type.— Cat. No. 21990 U.S.N.M. 



TRYPOXYLON PLESIUM, new species. 



This species belongs to the group oifrigidum and is closely related 

 to frigidum Smith, but may be separated from that species by having 

 the propodeum reticulate dorsally instead of with uniform oblique 

 striae. 



FeTYiale. — Length, 8 mm. Anterior margin of the clypeus with a 

 narrow median projection which is very feebly emarginate; a distinct 



