ODYNERUS. 2G3 



%. Form quite slender, a little depressed as with the Ancistro- 

 cerus tigris. Thorax slightly prolonged, wide before, retracted 

 behind. Post-seutel very freely truncate, offering a very sharp, 

 finely crenulate ridge. Metathorax vertical ; its truncation quite 

 flat, wide, occupying all its width, forming a plate of a very 

 angulate shape, as with the Ancistrocerus, notched at the 

 summit by the post-scutel (in the form of a double pentagon or a 

 double trapezium); this plate, surrounded by small, straight, 

 little salient ridges, which at their meeting form very sharp angles, 

 forming thus on each side an angle armed with a tooth ; their 

 superior angles forming two teeth, wholly spiniform, directed 

 vertically and placed behind the angles of the post-scutel. Abdo- 

 men slender; the first segment quite long and as wide as the 2d, 

 distinctly truncate at its base and offering on Us anterior face a 

 trace of a suture. Head and thorax rugosely, abdomen finely 

 punctured ; the border of 2d segment more strongly punctured, 

 offering, however, but one depressed band, only becoming thinner 

 as far as the end. Following segment rather strongly punctured. 



Insect black, clothed with a tawny or grayish pile ; a dot on 

 the front, another behind each eye, anterior border of prothorax, 

 tegular, a spot beneath the wing, posterior border of the scutel, 

 post-scutel, and the four little spiniform teeth of the metathorax, 

 orange; segments 1-4 of the abdomen bordered with orange; 

 bordering of the first wide and notched ; that of 2d wide and 

 regular; that of 3d and 4th narrow, often shortened at the sides. 

 Legs yellow, black at base. Wings washed with ferruginous. 



% . Clypeus ovoid, notably wider than long, a little notched 

 and bidentate, yellow. Mandibles spotted with yellow. On each 

 side of the frontal spot a place of golden hair. Antennas long 

 and thick, black, with a terminal ferruginous hook ; scape very 

 short, yellow beneath. Fifth segment ornamented with a yellow 

 incomplete border. Legs yellow; thighs varied with brown. 



9. Unknown. 



Hess. a. diff. — This species described simply from one male, is 

 necessarily incompletely characterized, but it is very easy to 

 recognize, from the form of the metathorax, of which the poly- 

 gonal and flattened plate I'ecalls those of the true Ancistrocerus, 

 but with this difference, that it is still more angular, the latero- 

 superior ridges not being arcuate. Despite the vestige of a 

 suture of the first segment, this Odynerus incontestably appertains 



