394 Dr. A. S. Packard, Jr's Revision of the 



wings iridescent ; flanks of the thorax distinctly corrugated on the 

 more convex surface, smooth and shining in the depressions. Legs 

 black, tarsi dark fuscous ; tibiae with two rows of spinules; tibial spurs 

 large, testaceous, and tarsal joints more than usually spinulate at tips. 

 Abdomen black, smooth and shining, supraiinal area one-half as broad 

 at base as long. 



Length, .22 inch. 



Brunswick, Me., (Packard). 



PASSALiECTJS Shuckard. 

 Passalcecus Shuck., Essay on Fossorial Hymenoptera, p. 188. (1837). 



Head shorter than in Cemonus, and much more cubical, being 

 transversely oblong, instead of square ; eyes rather larger than in 

 Pemphredon and Oemoims, oval ; ocelli placed on the vertex in a flat- 

 tened equilateral triangle. Front broad, narrowing very considerably 

 in % , in $ of even width above and below, somewhat concave and 

 slightly furrowed in the middle. Antennas placed farther apart than 

 in Cemonus, short and thickened, the joint continuous, not convex as 

 in Cemonus, 3d joint bent at right angles to the 2d, which is long; 

 clypeal region distinct sub-lozenge shaped, naked, clypeus raised along 

 the middle, slightly indenting the epicranum at the base of the antennae, 

 and the contour of the base is similar to that of the front, which at 

 the base of the labrum is tridentate. Labrum large, distinct, porrect, ex- 

 tending much beyoud the clypeus; it is triangular, the sides a little in- 

 curved, the point rather blunt; mandibles large, crossing one another 

 and widening very much towards the tips, which are broad oblique, 

 unidentate, edge very oblique, crenulated. 



Thorax long and narrow, twice as long as broad ; prothorax small 

 and narrow, produced in front. Meso-scutum very convex, curved 

 down in front, much shorter than broad, scutellum moderately long, 

 propodeum greatly produced. Enclosure transversely linear ; scutellum 

 longer, much longer than broad. Middle flanks scarcely horizontal, 

 while the hind flanks are inclined. Coxae stout ; trochanters subtri- 

 angular. Primaries very closely resembling Cemonus, but the wing 

 is shorter; the 2d costal cell is shorter and more angulated; the 1st sub- 

 costal is shorter; 2d much shorter than broad ; 1st median cell irregular- 

 ly rhomboidal ; the 3d or outer cell is much narrower; the 2d internal 

 cell is broader and shorter than in Cemonus. Secondaries much narrower 

 towards the apex than in Cemonus, the outer margin being straighter 

 and more oblique. The medio-costal recurrent is much farther from 

 the outer margin than in Cemonus, and their cells differ throughout. 



