ODYNERUS. 241 



flavis ; abdominis seginentorum 1', 2* margine flavo, 3'. 4 ! teniiiter 

 flavescente ; tibiis l is , 2 is linea llava ; alis ferrugineis macula radiali 

 fuse a. 

 Odyn. LaPlatce Sauss. Rev. et Mag. de Zool. XXII, 1870, 52, 2 J . 



9. Total length, 12 mm. ; wing, 9.5 mm. 



9. Form rather slender, very much as in 0. cubensis and 

 tibialis. Clypeus pyriform, strigate-punctate, terminated by two 

 little ferruginous teeth. Head and thorax densely punctate. 

 Post-scutel truncate, ridged but not crenulate. Metathorax 

 excavated in its whole width, forming on each side an indistinct 

 angle ; its superior edges convex, very sharp, their superior 

 extremity hardly separated from the post-scutel by a fissure, not 

 forming salient teeth ; the inferior edges straight or a little arched 

 concave. Abdomen polished, silky, the first segment as wide as 

 the 2d, almost sharply truncate. 



Black; scape ferruginous beneath; a fine line along the poste- 

 rior edge of prothorax and a very slender one along the anterior 

 margin, on each side, two spots on the tegulas, a mark under the 

 wing, a line on post-scutel, and the superior edges of metathorax, 

 yellow. Segments 1, 2 of the abdomen narrowly margined with 

 yellow ; the extreme margin of the 1st brown ; segments 3-5 

 narrowly margined with brown or yellowish. Knees and claws 

 ferruginous. Tibia? 1st and 2d anteriorly with an indistinct yellow 

 line. Wings ferruginous along the anterior margin; the radial 

 cell brown. 



Bess. a. cliff. — This is possibly the same as 0. prsecox] and I 

 should not have distinguished this from it, if in the description of 

 prsecox it was not said that the metathorax was rounded, while 

 here the superior" edges are very sharp. — It much resembles 

 tibialis, but the livery is rather different and it varies also in its 

 metathorax not sharply bidentate, its abdomen not as conical, its 

 first segment not as sharply truncate, shorter, etc. — From zonalus 

 it differs in its livery and the same changes in the form of the 

 prothorax. 



Hab. The Argentine Republic. Buenos Ayres. 



"a?. O. tibialis Sauss. — Niger, cinereo-hirtus ; dense punctatus ; thorace 

 qnadrato, 9 lougiore quam latiore, % cubico, depresso ; metanoto bi- 

 dentato, acutissime rnarginato; abdomine valde conico basi acute trun- 

 cato et cantbnm acntum transversum efficiente ; segmentorum 2-5 

 margine punctato. Macula mandibularum, pronoti margine, tegulis, 

 '6 



