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



usual ; fore femora slightly expanded ; fore tibite naked ; tarsi finely 

 ciliated ; hind tibiae with fine setiferous tubercles especially abundant 

 along the angles; first joint of tarsi'much shorter than the remaining 

 joints. 



Abdomen equalling the length of the head and thorax together, 

 broad and much flattened, more than half as broad as long, beneath 

 unusually concave, basal ring broad and short; tip rounded spatulate. 



The remarkably short head, broad, short body, the deflexed clypeus, 

 the short triangular front, unidentate mandibles, the flattened fore 

 femora, angulated prothorax and meso-thoracic flanks, the concave un- 

 der side of the abdomen, the great differences in the neuration and 

 its undersized species will easily serve to distinguish this interesting 

 genus. In its narrow clypeal region, as compared with the broad 

 antennal region, its short compact form, its evenly, closely jointed an- 

 tennae and short cubical thorax it reminds us of Oxybelus, though not 

 closely related by affinity, being an isolated generic form standing out 

 from the line connecting Crabro conjiaenta and its allies, with 

 Cerceris. 



The front of the head instead of being oblong elliptical as usual in 

 this group, is round, the clypeal region is not so broad as in Crabro, 

 while the antennae are inserted much farther apart. Seen laterally 

 the thorax is no longer than high ; the meta-thorax is suddeuly verti- 

 cally deflexed, and is thus parallel with the front of the prothorax, 

 where usually in Crabro it falls away at a less angle towards the inser- 

 tion of the thorax. 



In the wings the first sub-costal space is long and crescent-shaped, 

 not lozenge-shaped as usual. The first median space is rhomboidal 

 and smaller than usual, instead of being as usual long and lozenge- 

 shaped, and its outer end terminates in the middle of the wing, while 

 in the genus Crabro and allies, it terminates at or near the outer third 

 of the wing; first submedian space does not extend to the middle of 

 the first median, being very short; second submedian is much longer 

 than first submedian space, whereas it is usually much shorter, and 

 lanceolate in form, and is externally regularly rounded, not truncated 

 as usual. The second median space partially obsolete externally, more 

 regularly rhomboidal than usual, and the two upper sides forming a 

 nearly straight line. In the secondaries the first submedian space is 

 one-halt' shorter than in the other genera. 



A. ocellatus, n. sp. 



9 . Whole body coarsely punctured, more so than usual in Crabro. 



