8 PEOCEEDINGS OF THE NATION^AL MUSEUM vol.76 



As I have shown in my description of Angitia galleriae ^ the de- 

 pressed petiole is, in some cases at least, of not even specific sip^nifi- 

 cance. The same is true to some extent of the impression of the 

 petiolar area of the propodeiim, the fracture of the nervellus, and the 

 depth of the lateral furrows on the petiole. Most of the genera in 

 the Campopleginae are based on such trivial and variable characters 

 as these, and the classification of the group would be much simplified 

 and brought nearer the truth were many of the genera suppressed. 

 It is my opinion that there is no generic difference between Camipop- 

 lex^ Euliiivrwnay Sesioplex^ Angitia Holmgren, Idechthis Foerster, 

 and C aiTt'poletidea Viereck, while Diodes Foerster differs only in its 

 lack of the alar areolet. For the time being, however, I shall 

 consider them distinct genera. 



This discussion is gone into in order to explain the generic place- 

 ment of the following new species. It may have been described by 

 Viereck in his "A Preliminary Review of the Campopleginae in the 

 Canadian National Collection," Ottawa ; but, because of his use of so 

 many trivial characters in his generic keys. I have found it very diffi- 

 cult to use them, and in the present instance impossible to place the 

 species in any genus satisfactorily. 



SESIOPLEX CANADENSIS, new species 



Female. — ^Length, 7.5 mm. ; antennae 4 mm. 



Head finely coriaceous or shagreened, the face, clypeus, and irons 

 finely, closely punctate ; temples somewhat sloping, straight for most 

 -of their length, then abruptly turned inward to the occipital carina, 

 the cephalo-caudad length nearly as great as short diameter of eye; 

 diameter of lateral ocellus very nearly as long as ocell-ocular line; 

 eyes slightly emarginate opposite antennae; face very slightly nar- 

 rower than frons; malar space hardly two-thirds as long as basal 

 width of mandible; clypeus broad, not at all separated medially, its 

 apical margin broadly submucronate medially; antennae stout, fla- 

 gellum with" about 33 joints, those beyond apical third transverse. 

 Thorax short ovate, sculptured like the head but even more opaque, 

 even the speculum entirely opaque; pronotum somewhat rugulose in 

 lower lateral angle; scutellum strongl}'^ convex; propodeum very 

 finely rugulose, the petiolar area somewhat impressed; legs moder- 

 ately stout, hind basitarsus as long as rest combined, inner calcarium 

 reaching slightly beyond middle of basitarsus; areolet narrowly ses- 

 sile to subpetiolate ; recurrent vein beyond middle ; nervulus strongly 

 inclivous; postnervulus broken distinctly below middle; exterior 

 angle of second discoidal cell strongly acute ; nervellus weakly broken 

 near bottom, somewhat inclivous, discoidella wanting. Abdomen 



3 Proc. U. S. Nat. Mus., vol. 58, 1920, p. 266. 



