280 HYMENOPTERA. 



This insect is identical in coloration with the foregoing (M. exacta and M. amulce), 

 but it may be easily separated from either of them by the very different structure of 

 the pygidium. This has, along the sides, a distinct keel, and in the middle at the 

 apex are two short, stout keels, which do not unite at the apex. The oral region is 

 normal and bears no teeth ; the wings are hardly lighter at the base, and are more 

 deeply violaceous ; the first cubital cellule is longer compared to the radial ; and the 

 tubercle on the median segment is stouter. 



Head narrower than the thorax; the vertex sparsely covered with long blackish 

 hairs and laterally with a whitish pubescence ; the cheeks and the oral region densely 

 covered with long white hair ; the apex of the clypeus rounded, shining ; the cheeks 

 laterally ending in two blunt piceous roundish short tubercles. The eyes large, 

 reaching quite to the top of the head, the incision wide ; the head only moderately 

 developed behind them and rather sharply narrowed. The scape of the antennae has 

 short white sparse hair above, the flagellum a brownish microscopic pile ; the third 

 joint is, if anything, longer than the fourth. The prothorax is coarsely punctured, its 

 apex with a dense band of white pubescence, and almost truncated in the middle. 

 Mesonotum shining, and having large irregular, mostly widely separated, punctures, 

 its hair long and black. The tegulae large and shining, the underside with pale fuscous 

 hair; they are not much developed posteriorly. The scutellum broadly convex, 

 coarsely punctured ; the base with some long black hairs, the rest covered more thickly 

 with long white hair. The median segment reticulated, distinctly narrowed towards 

 the apex, which has an oblique slope, the top of the slope, however, being rounded ; at 

 the base in the middle is an elongated area, rounded at the apex, where it terminates 

 in a tubercle ; at its sides at the extreme base is a small elongate depression, densely 

 covered with pale pubescence ; the rest of the segment with whitish hair, and at the 

 sides above there is a white pubescence. The basal region of the propleuree strongly 

 punctured, the apex excavated, crenulate at the base below ; the mesopleurae punc- 

 tured, densely covered with white pubescence ; the metapleura at the apex punctured. 

 The basal segment of the abdomen black at the anterior half, shining, with some 

 widely separated, scattered punctures ; the base stoutly toothed ; the second segment 

 with some indistinct scattered punctures along the sides, at the apex fringed with 

 rufous hair ; the other segments with their basal halves impunctate, their apical halves 

 clothed with rufous hair. The pygidium punctured, except at the middle before the 

 keels ; down the sides run stout keels, and in the middle is a small depressed area 

 bounded by stout keels, which are curved and unite at the apex ; the hair is rufous 

 and rather long. The hypopygium is punctured at the sides ; the apex terminates in 

 three rounded projections, in front of which is a stout raised, oblique point, this being 

 rounded at the end. The basal ventral segment is distinctly keeled in the middle, 

 which is slightly waved; the sides with a few punctures. The second ventral 

 segment is punctured ; the others are impunctate and fringed with fulvous hair. The 

 legs thickly covered with long glistening white hair. The wings are lighter along the 



