ODYNERUS. 291 



Insect black, bristling with grayish hair (among fresh specimens 

 the abdomen is almost velvety). A spot on the front, another 

 little one behind each eye, anterior border of prothorax, tegulae, 

 a spot beneath the wing, two on the scutel, post-scutel, and a 

 spot on each side of this on the summit of metathorax, yellow or 

 a little red. The first two segments of the abdomen bordered 

 with yellow; the border of the first joined on each side with an 

 oblique red or yellow spot; the segments ( 9 3-4), % 3-5 bordered 

 with a fine yellow edging. Legs yellow, at the base black. 

 Wings transparent, a little smoky; nervures brown. Wing scales 

 spotted with red or brown. 



%. Clypeus yellow, strongly punctured, wider than long; its 

 inferior extremity slightly prolonged and truncate in middle. 

 Mandibles, scape of antennae beneath, inner border of orbits, and 

 femora above, yellow. Hook of the antennas ferruginous. 



Bess. a. cliff'. — This resembles divers species, particularly the 

 0. arvensis % , but the clypeus is much more coarsely punctured, 

 wider in proportion, with the extremity narrower and not biden- 

 tate. It differs from others : from 0. arvensis, Boscii, Hidalqi, 

 and Iturbidi by its metathorax, which is not bidentate and very 

 much more excavated. — It is easily distinguished from the 0. 

 foraminatus & by the form of its clypeus, by its more coarsety 

 punctured thorax, by the metathorax surrounded by more salient 

 borders, and very much more rugose, not forming behind the 

 post-scutel the two little separating teeth; by the two yellow 

 spots of the scutel ; by its very conical abdomen, truncate at its 

 base, w r ith a sharp ridge. But it offers an appearance wholly 

 similar to the 0. turpis; the same size, the same form, the same 

 livery, so far that one would readily take it for the male of that 

 species. However, it differs from it essentially by the borders of 

 its metathorax, which are blunted, rugose, and not at all tren- 

 chant, while in the species of this group the ridges are in general 

 more trenchant at the summit among the males than in the 

 females. Yet the resemblance is such between these two in- 

 sects that I remain in doubt if they are not the two sexes of the 

 same species, the rather that with the 0. turpis (?) the ridges 

 are often blunted toward the base. 



Bab. The "United States. 2 % from Tennessee. 



