Fossorial Ilymenoptera from the Khasia Hills. 63 



median segment is, in some examples, distinctly transversely 

 striated. 



Tliis is probably a variable species as regards coloration, 

 size, and scnlptnre, 



Psen niyrinervis, sp. n. 



Niger, facie clypeoqiie dense argentco pilosis ; petiolo Icevo ; alis 



hj-aliiiis, nervis stigmateque nigris. $ . 

 Long, n mm. 



Antennae black ; the scape sparsely covered with longish 

 white hair; the Hagellutn almost bare. Head shining, the 

 face, clypen>;, and the outer orbits, except at the top, densely 

 covered with long silvery hair ; the front and vertex finely 

 and closely punctured, more sparsely near the eyes ; they 

 are covered with long black hair ; the front is not furrowed. 

 Mandibles sparsely covered with white hair, and rufous 

 before the teeth. Pro- and mesothorax sparsely covered 

 with long fuscous hair ; the metathorax, except at the base, 

 more thickly with long white hair; the mesonotum closely 

 and moderately strongly punctured ; the scutellum impunc- 

 tate ; the basal area on the median segment strongly longi- 

 tudinally irregularly striated, the central more widely 

 separated than the lateral; the apex of the segment has an 

 oblique slope ; in the centre above there is a shallow area, 

 rounded at the top ; the apex with the sides bordered by 

 oblique keels ; the middle with a deep sharply bordered 

 furrow, which becomes wider and deeper towards the apex ; 

 the sides have three stout oblique keels. Pro- and meso- 

 pleurse smooth, the base of the latter Math a crenulated 

 furrow ; the upper part of the mesopleurse roundly raised 

 and bordered below by a narrow furrow. The apex of the 

 metapleurpe is reticulated and bordei-ed on the inner side by 

 a stout keel ; the base is deeply depressed. Mesosternura 

 smooth, shining, and covered with long fuscous hair ; the 

 broad middle furrow has a central keel. Legs covered with 

 longish white hair ; the calcaria, spines, and claws rufo- 

 lestaceous. Wings hyaline, with a slight fuscous tinge; the 

 first cubital cellule is half the length of the third, and 

 receives the recurrent nervure in the basal fourth; the second 

 recurrent nervure is interstitial. Abdomen, including the 

 petiole, smooth and shining ; the pygidial area closely acicu- 

 lated, the sides with a few punctures margined by a distinct 

 keel. 



The transverse median nervure is not quite interstitial, it 

 l)eing received shortly behind the transverse basal; the apex 



