o 



50 THE CANADIAN ENTOMOLOGIST. 



postscLitellum most frequently with a median longitudinal 

 furrow or depression, or at least one or the other with such a 



furrow, rarely simple Sphex, Linne. 



Clypeus anteriorly witJi a median emargination or incision ; 

 scutellum and postscutellum normal, without a median longi- 

 tudinal furrow Isodontia, Patton. 



4. Claws with only one tooth beneath 5. 



Claws with 2-5 teeth beneath 6. 



5. Species metallic blue or violaceous ; marginal cell at apex narrowly 



rounded ; cubitus in hind wings interstitial with the transverse 

 median nervure ; mandibles not especially long; tibiae more sparsely 

 and feebly spined ; maxillary palpi 6-jointedj labial palpi 4- 



jointed Chlorion, Latreille. 



Species, except sometimes the abdomen, not metallic ; marginal cell at 

 apex truncate or broadly rounded ; cubitus in hind wings origi- 

 nating beyond the transverse median nervure ; mandibles unusually 

 long ; tibiae in ? strongly spined ; maxillary palpi 6-jointed ; labial 

 palpi 5-jointed Pronaeus, Latreille. 



6. Last ventral plate in $ compressed, almost carinate ; claws with 2 



teeth 7 . 



Last ventral plate in 9 convex, not compressed ; claws with 2-5 teeth 

 beneath S. 



7. Clypeus medially produced, with a deep sinus on each 



side Palmodes, Kohl. 



Clypeus obtrapezoidal, truncate anteriorly, entire ; eyes within 

 parallel Calosphex, Kohl. 



8. Claws with 2 teeth ; clypeus convex, anteriorly subemarginate 



medially, without a reflexed rim ; anterior tarsal comb short ; 

 transverse median nervure in hind wings short . . Harpactopus, Smith. 

 Claws with 3 to 5 teeth ; clypeus subconvex, with a more or less 

 distinct reflexed rim anteriorly ; anterior tarsal comb long. 



Claws with 3-4 teeth ; clypeus anteriorly slightly rounded, and not 

 at all, or only slightly, emarginate ; transverse median nervure 

 in hind wings curved or somewhat curved, the cubitus Inter- 

 stitial^ or nearly, with it Parasphex, Smith. 



Claws with 4-5 teeth ; clypeus anteriorly truncate, with a median 

 emargination ; cubitus in hind wings originating beyond the 



