WALSH DESCRIPTIONS OF N. AM. HYMENOPTERA. 93 



as the hind femora are as Say describes those of his pollinctorius, 

 "yellow at base" and black at tip. As in Say's pollinctorius o"2 

 (but not in my 2), the 2d abdominal joint has a lateral yellow spot 

 at tip ; but the entire metathorax is black immaculate. As com- 

 pared with my 2 , the abdomen is more strongly sculptured, so as 

 to be opaque instead of subpolished. 



Genus EXOCHUS, Gravenhorst. 



Gravenhorst has placed the group to which this genus apper- 

 tains between the groups Ichneumon and Trogus, which, as 

 Bridle has well observed (p. 298), are too closely allied to be thus 

 separated, and with which it seems to have no other analogy than 

 the possession of a very short ovipositor. Its abdomen indeed is 

 as sessile as that of any Pimpla (though there is a very consider- 

 able difference in different species in the basal breadth of its first 

 joint), and it is scarcely correct to call it, as Gravenhorst does, 

 subsessile. The protuberant face shows its connection with 

 Jlfetopius, and in fact most of the Pimploid genera have a more 

 or less prominent tubercle on the face, which in some species, e.g. 

 Glypta tuber culifrons, n. sp., is very prominent. My species 

 show a considerable difference in the comparative length and 

 breadth of the first joint of the flagellum, and consequently in that 

 of the succeeding joints also, the first joint being in Icevis 2 and 

 albiceps % only twice as long as wide ; in albifrons 2 , antiuli- 

 crus %, and atriceps %, v\ times as long as wide; and in albi- 

 frons % 35 times as long as wide. There is a similar difference in 

 the incrassation of the hind femora, which in Icevis 2 are only 

 twice as long as wide, in atriceps % 2\ times, and in the other three 

 species 2 J times as long as wide. In this genus there are but three 

 bulla?, A, CD, and E ; A indistinct and sometimes obsolete on the 

 forward end of the areolar cross-vein, CD located well forwards 

 on its vein, and E rather nearer to the angle than to the tip of its 

 vein. Judging from the single species of which I possess many 

 specimens, the size and coloration are both pretty constant. 



Section 2, Cresson. — Areolet obsolete. 



ExOChllS liCVis, Cress. — 5* — Head opaque, with confluent, rather fine 

 punctures and pubescence on the face, the punctures finer and more sparse 

 on the subpolished vertex. Face, when viewed in profile, projecting be- 

 yond the eyes by a distance equal to their shorter diameter. Clypeus 

 glabrous and polished. Mandibles and the upper edge of the face rufous. 

 Palpi yellowish-white. Antenna; f as long as the body, brown-black, 



