ODYNERUS. 199 



manner that there exists one anterior and one superior face, dis- 

 tinctly separated by a trenchant ridge which bears the indistinct 

 suture. This segment is not campanula te, but almost as wide 

 before as oil its posterior border. 1 The 2d segment is hardly 

 wider than the first. 



b. First abdominal segment more rounded anteriorly, rather like a square bell. 

 (Metathorax slightly prolonged behind the post-scutel ; then truncate ; its 

 concavity rounded. Body rugose.) 



36. A. llistrio Lep. — Gracillimus, rugosissime punctatus ; metanoto 

 rugosissimo profunde foveolato, foveola? canthis valde promiuentibus 

 et acutis ; niger, antennis, macula frontali et oculari, pronoto antice, 

 tegulis, macula subalari, post-scutello, metanoto utrinque, abdominis 

 primo segmento pedib usque runs ; alis cyanescentibus. 



Variat. Post-scutello et abdominis segtueutorum 1', vel 1', 2' margiue, 

 amantiacis. 



Odynerus histrio Lep. St. Farg. Hymenopt. II, 638, 23 2 (1841).— Sauss. 



Vespides, I, 208, 112 ; III, 242. 

 ? Odynerus ammonia Sauss. Vespides, I, 144, 30 (1852). 



Total lengtb, 11 mm. ; wing, 9 mm. 



9 . Form very slender and lengthened. Clypeus pyriform, 

 rugose, terminated by a little biangulate border, appearing bi- 

 dentate, because of a terminal fossette. Head densely and strongly 

 punctate ; thorax coarsely cribrose, with very large depressed 

 points ; the punctures a little separated ; prothorax slightly 

 retracted before, subangulate ; metathorax retracted, rounded, 

 but its hinder plate very strongly excavated, offering a fossette, 

 punctured, rugose, bordered all around by very salient and 

 trenchant ridges, of which the summit is notched and sometimes 

 separated from the post-scutel by two grooves. First abdominal 

 segment lengthened, a little narrower than the 2d ; its superior 

 face very rugose, as strongly cribrose as the thorax, but more 

 densely ; covered like the metathorax with enormous reticulate 

 rugosities, and offeritig a vague depression on its anterior part; 

 its irregular suture, placed but a little on the anterior face and 

 often followed by a fluting. Second segment prolonged and 

 slender, strongly punctured ; its border very coarsely punctured. 



1 In the fig. cited, this segment is badly represented ; it has not this 

 rounded form. 



2 Page 639, in place of 3 lines, read 5 lines. 



