MONOBIA. 133 



Vespa 4-dens Lixx. Syst. Nat. II, 95, 15 (1767).— Amcen Acad. VI, 413 



Mueller, Ed. Lin. II, 881, 15. — Christ Hymen., 234. — Illiger, 

 Com p. Ins. rarior., 30, 92. 



Vespa uncinata Fabr. Syst. Ent., 367, 22 (1775). — Syst. Piez., 259, 31.' 

 Oliv. Encycl., VI, 685. 



Vespa cincla-nigra Degeer. Mem. Ins. Ill, 583, 8; tab. xxix, fig. 12. 



Odynerus uncinates Lep. St. Farg. Hym., II, 619, 9. 



Odynerus quadridens Say, Bost. Journ., I, 386, 3 ; Ed. Le Conte, II, 766, 3. 



Monohia quadridens Sauss. Vespides, I, 97, 4; III, 168. 



Monobia uncinata Sauss. Ibid. I; pi. xvi, fig. 1 (bad figure). 



• Total length, 20 mm. ; wing, 17 mm. 



Large. Head densely punctured, often presenting on the 

 vertex a little depression. Thorax densely punctured ; prothorax 

 with a slender margin; mesothorax offering above the scutellum 

 two distinct grooves; scutellum feebly convex, but little divided, 

 post-scutel subdivided, not crenulate; metathorax slightly re- 

 tracted, offering on its posterior face a subconcave furrow, very 

 finely striate, distinctly margined (at least at bottom) and armed 

 on each side with a spine. (The upper ridges are often a little 

 effaced by the punctures.) Abdomen smooth, ovalo-conical, 

 covered with fine scattered punctures; the first segment perfectly 

 sessile, truncated before, punctured on its anterior face, as wide 

 as the 2d and divided by a groove on its upper face ; the 2d 

 quite strongly punctured with separated points, more and more 

 dense toward the posterior border. 



Insect black, shining; two great spots on the prothorax, the 

 post-scutel and the first segment of the abdomen above, whitish. 

 Wings of a black violet. 



9. Clypeus black, pyriform, punctured, terminated by two 

 dentiform, diverging, carinated angles. 



% ■ Clypeus whitish, margined with black, terminated by two 

 separated teeth, divided by a wide slightly concave border. 

 Antenna? terminated by a hook. 



1 The description of Linneus is incomplete, that of Fabricius touched 

 with error, and the name has two typographical faults in the Syst. Piez. 

 Yet there can be no doubt regarding the species. Linne has counted a* 

 teeth the two angles at bottom of metathorax which receive the articulation 

 of the abdomen. Fabricius does not notice the metathoracic teeth, 

 doubtless because the abdomen, raised and pressed against it, concealed 

 them from his sight. 



