ODYNERUS. 355 



yellow margin of prothorax, and strong punctures. It has much 

 the form of 0. acolhuus, but differs by its size (twice as large), 

 its stronger punctures, its higher head, its first abd. segment, not 

 petiolate at base, its rather different livery, its immaculate 

 antennas, flanks and tibia, ?. 



Hab. The temperate part of Mexico. Oriental Cordillera 

 (Suniichrast). 



B. Metalhorax armed superiorly with two tubercles, sometimes 



very small. 



151. O. NallMUS Sauss. — Niger, gracilis, elongatus, crassissime cribri 

 instar punctatus; pronoto bidentato; post-scutello antice transverse 

 cristato, postice cribrato ; metathorace producto, rotundato, foveola 

 punctata instructo, superae bituberculato ; abdominis 1° segmento 

 subpetiolato, 20 elongato ; reliquis tenuissiine punctatis ; pronoti mar- 

 gine antico, tegularam limbo, fascia scutelli, abdominis segmentorum 

 1', 2> margine maculaque tibiarum, sulfureis. — £. Clypeo nigro, rotun- 

 dato, subbidentato. 



Odyn. Nahuus Sauss. Revue de Zoolog., XXII, 1870, 140, 32, £ . 



Total length, 8.5 mm. ; wing, 5.5 mm. 



9 . Small. Very slender and elongate, having much the form 

 of 0. Tacubayde. Head a little higher than wide, not much 

 swollen behind. Thorax elongate; anterior margin of prothorax 

 crested, its angles spiniform. Scutel having on its anterior part 

 a fine transverse crest, finely crenulate ; its hinder part behind 

 the crest transverse, cribrose, transversely square, very obtusely 

 angulate. Metathorax prolonged, rounded, having a distinct 

 concavity, nearly reaching the post-scutel ; "this cavity cribrose 

 like the rest of metathorax, its margins quite rounded, effaced, 

 but having on the superior part two little rounded tubercles. 

 punctured like the rest. Articular valves of the apex of the 

 metathorax not spiniform, more flattened. Head and thorax 

 exceedingly coarsely cribrose; the metathorax not as coarsely 

 so, but yet strongly. Abdomen elongate. The first segment 

 Cribrose like the thorax, funnel-shaped, a little petiolate; about. 

 as wide as long, convex, and a little constricted before its margin. 

 Second segment cylindrical, much elongated, though not strongly 

 cribrose. The following segments quite finely punctured. 



Klack, a little silvery sericeous. Head ami antenna quite 



