172 HYMENOPTERA OF AMERICA. [PART I. 



Head and thorax finely and very densely shagreened j abdomen 

 punctured, a little velvety. 



[nsecl black, covered with gray hair. Two lateral spots on 

 the summit of the clypeus ; another between the antennae, a dot 

 behind each eye. a narrow border on the prothorax, a spot beneath 

 each wing, two on the posterior border of the scutellum, two dots 

 on the wing scales, and the border of segments, 1, 2, 3 of the 

 abdomen, sulphur-yellow; there is often a yellow dot at the base 

 of the scape of the antennae and upon the anterior tibiae. The 

 yellow hands of the abdomen are regular; the first often slightly 

 enlarged al the two extremities, the two others at times retracted 

 in the middle, and complete beneath. Wings transparent, washed 

 with brown ferruginous. Wing scales black, spotted with yellow. 



Var. Clypeus and antennas black. 



%. Size same as the female. Clypeus yellow, armed with two 

 shorl teeth separated by a semicircular emargination ; its inferior 

 margin finely bordered with black; mandibles and labrum black. 

 Scape of the antenna? in general marked with a yellow line; hook 

 black. Wing scales, scutellum, and the flanks, in general, black, 

 without yellow spots; the fourth segment carrying a narrow yel- 

 low band interrupted above. Tibia? yellow before. Post-scutel 

 divided by a little medial groove. The superior angles of the 

 metathoracic plate pronounced. 



Hess. a. diff. — Tins species is peculiar in its wholly black 

 antenna? and in a very marked tendency to lose its yellow orna- 

 ments. Its thorax is short and little arched. Its abdomen has 

 a velvety appearance. It has the form of the 0. Catskillensis, but 

 the first abdominal segment and the thorax are a little less wide ; 

 its size is a little greater. The % has the clypeus sensibly less 

 bidentate than the North American species of this group. It is 

 closely allied to the 0. Bustamente. (See the description of this 



Speeies.) 



I/uh. The hot and temperate regions of Mexico. Cordova. 

 Jalapa, the .M ichoacan. 



H. A. Ilustameiiti Sauss. — 0. Santa-Amur Bimillirans, niger; clypeo 

 integro ma cutis 4 flavis ; thorace Iatiore, pronoto latissimo, tenuiter flavo 

 marginato, metanoto angustiore, matins inferis flavo-ornatis ; macula 

 subalari et scutelli fascia interrapta, flavis ; abdomine velutino, basi 

 lato. segmentis L-5 flavo-marginatfs ; tegulis flavo-bipunctatis. 9. 

 Odgnerus Bustamente Sauss. Revue et Mag. de Zool., IX, 1857, 273, £. 

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



