296 HYMENOPTERA OP AMERICA. [PART I. 



tion as the 0. Iturbide and Hidalgi (var. Mex.) ; but it differs 

 by its smaller size, by its bidentate post-scutel, by its smaller 

 concavity which only occupies the middle. The male greatly 

 resembles the 0. inolestus, but is distinct from it by the meta- 

 thorax having its borders more regularly rounded, regularly 

 punctured, not rugose, not angulate at the summit, nor quite so 

 elevated as to be separated from the post-scutel by a fissure ; by 

 the more oval abdomen, by its antennae, red in their first moiety, etc. 



The species closely approaches also to the colors of the 

 Morelii, and the Ancistrocerus tuberculiceps. (See the descrip- 

 tion of these species.) 



Hah. The temperate parts of Mexico. I took 4 9 and 9 % in 

 the beautiful valley of Mextitlan ; one ? on the confines of 

 Morelia, in Mechoacan ; and 2 9, 3 £ in the hot parts of the 

 province of Mexico (Cuautla). 



1©!>. O. HoiBBaradillllls Sauss. — Satis gracilis, nigro-velutinus, pilis 

 longis fulvis hirsutus ; post-scutello baud acute truncato ; metanoto 

 baud angulato ; puncto post-oculari, pronoti, tegularum, abdomiuisque 

 segmentoruni 1-3 niargine, flavo ; nost-scutello fascia llava ; alis infus- 

 catis, fusco-purpureo nitidis. — Clypeo J nigro ; ^ aurautio, basinigro. 



Odt/n. Romandinus Sauss. et Vespides, I, 1S4, 79. 



9 . Total length, 11 mm. ; wing, 8.5 mm. 

 % . Total length, 9 mm. ; wing, 8 mm. 



Rather slender, very finely punctured and velutinous throughout. 

 Post-scutel depressed, not sharply truncate. Metathorax very 

 slightly excavated, not angulate ; the excavation not margined ; 

 superiorly, continued without limits from the superior part; the 

 lateral edges continued with the inferior edges. Abdomen ovate- 

 conical, a little depressed ; the first segment not as wide as the 

 second, bluntly truncate anteriorly, and more strongly punctate. 

 Second segment having at base beneath a transverse tubercle. 



The whole insect of a deep velvet black, and all bristling with 

 long fulvous hair. Antennae and head black; a little yellow spot 

 behind the eye. Anterior margin of prothorax with a narrow 

 yellow band ; margin of wing scales, a fascia on the post-scutel, 

 and the margin of the 1-3 abd. segments narrowly yellow ; the 

 3d margin quite narrow. Wings fuscous, with brown and violet 

 iridescence. The ornaments are of a golden sulphur-yellow. 



