ODYNERUS. 321 



wing, post-scutel, ridges of metathorax, tegulae, the margin of all 

 the abdominal segments, and two free spots on the - 2d segment, 

 orange or brick-red ; feet ferruginous ; coxae maculate with fer- 

 ruginous. Wings a little smoky. The rufous margin of the 

 second segment is wide and regular ; that of the first fused on 

 each side with a little spot; the fascia of the last segments some- 

 times pale or yellow. 



Bess. a. cliff. — This species is noticeable for its velutinous 

 body and rufous ornaments; by its 2d segment as strongly punc- 

 tured as the 1st, and the thorax, with its margin not channelled, 

 scarcely reflexed at all, which distinguishes it from 0. collega. 

 It differs from 0. Xantianus, by its more cylindrical abdomen, 

 its 2d segment not short, and post-scutel not elevated. 



Hab. Mexico. I caught this species in the "tierras templadas," 

 South of Mexico. 



*** No free yellow spots on Vie first two abdominal segments. 

 Observation. — Compare also the Sections * and **, for the varieties 

 destitute of spots which the reader may be inclined to confound with the 

 species of this group. — Comp. principally 0. collega, 0. Kennicottianus, 

 toltecus. 



\%"t. O. PennsylvanicilS Sauss. — 0. pedestri affinissimus, gracil- 

 limus ; niger, punctatus ; fascia scapi, pronoti et abdominis segmentorum 

 1>, 2', 4 1 margine, post-scutello maculaque subalavi, tibiis tarsisque 

 flavis; tegulis rufis.— 9 . Clypeo bidentato flavo. 



Odyn. Pennsylvania^ Sauss. Et. Vespid., Ill, 257, 134 (1854). 



$. Total length, 9 mm. ; wing, 7 mm. 

 % . Total length, 8 mm. ; wing, 6 mm. 



Quite approximating to 0. pedestris. The size a little smaller; 

 but the same form, only more slender. Head orbicular. The 

 punctures about the same, but the clypeus. more finely punc- 

 tured. The concavity of metathorax not margined superiorly by 

 wrinkled rugosities; its summit sooner occupied by reticulate 

 large punctures. The abdomen very slender, cylindrical; the 

 1st segment having the same form as in 0. proximus, rather 

 small, elongate, a little depressed, having often merely a vestige 

 of a suture. The margin of the 2d coarsely punctured, but only 

 narrowly sulcate, or not at all channelled, only slightly depressed. 

 9. Black. Clypeus quite black. A spot on the mandibles, 

 labrum, a line on the scape of the antennae, a spot in the sinus of 



