ODYNERUS. 165 



Var. Two yellow spots at the base of the clypeus. Clypeus 

 yellow with a black dot in the middle. 



%. Clypeus strongly bidentate, polygonal, and with the la- 

 brum and the mandibles before, yellow. Hook of the antennae very 

 small, black. Border of the concavity of the metathorax much 

 more salient; its superior angles elevated into two pyramids 

 separated from the post-scutellum by two fissures. Lateral 

 angles of the metathorax prolonged in the form of a spine-like 

 tooth. Segments 5 and 6 adorned with a narrow yellow edging; 

 knees, tibia}, and tarsi yellow. 



Var. % . No yellow spots beneath the wing nor on the scutellum 

 (Illinois, Wisconsin). 



Observation. — The markings upon this species are of a sulphur- 

 yellow. The first two segments of the abdomen have a regular 

 border; that of the first is at times a little enlarged in the middle. 

 The bordering of the segments 3-5 is but a narrow edging. 



This Oclynerus is literally the American representative of the 

 0. antilope of Europe. It has the same form, the same sculpture, 

 the same design, and cannot be distinguished but by the less 

 developed yellow ornaments and by a little larger size. 



Bess. a. diff. — This species is especially characterized by the 

 form of the metathorax, the plate of which is shining as with the 

 0. antilope, and has the inferior borders more salient. It is 

 distinguished also by its great size, by its form, lengthened but 

 not narrow, by the regularity of its abdominal bands, and by its 

 livery of yellow ornaments, but little developed and constant. 

 It differs from the 0. unifasciatus by its large size, by its 2d 

 abdominal segments having the border not upturned, by its 

 numerous yellow bands. 



Hab. North America, the eastern portion, where it is very 

 common. I possess 20 of the 9 and 4 % } which have been taken 

 in Canada, Lake Superior (Agassiz), Connecticut (Norton), 

 Pennsylvania (Rathvon), Tennessee (Fuchs), Illinois (Walsh), 

 Missouri, Louisana (Norton). 



IB. A. SpninoHap Sauss. — Validus, nfger, nitidua, punotatns, statttra <>t 

 form is (). capra similliraua, at metanoti disoo 9 wajtis aonte marginato 



supra angulosiore; clypeo, scutello et thoracis lateiibus iiiini;uula!is ; 



