NORTH A^rERICAN DIGGER WASPS— FERNALD. 309 



KEY TO THE SUBGENERA AXD SPECIES OF THE GENUS CHLORION. 



1. Second cul^ital cell of fore wing higher than broad 2. 



Second cubital cell of fore wing as broad or broader than high, rectangular, or 



rhomboidal 17. 



2. Claws with one tooth (Subgenus Clt/orio)/) 3. 



Claws with two or more teeth 4. 



3. Body bright blue or green Cldorion cyaneum Dahlbom (p. 313). 



Body bronze blue Cldorion cyaneum ;rrurium Patton (p. 317). 



4. Claws with two teeth; clypeus with a median truncated lobe and a sinus on each 



side (Subgenus Palmodes) 5. 



Claws with three to six teeth; clypeus without a median truncated lobe but often 

 with ii median emargination or notch (Subgenus Pnononyx) 8. 



5. Abdoinen black or at most only faintly brownish or ferruginous. 



Palmodes Ixriventris (Cresson) (p. 318). 

 Abdomen more or less ferruginous or yellow 6. 



6. Abdomen entirely ferruginous or yellow 7. 



Tip of abdomen black ... Palinodes abdominalls (Cresson) (p. 322). 



7. Wings yellow; female with seven comb teeth. Palmodes prwstans (Kohl) (p. 328) . 

 Wings filiginous; female with six comb teeth. 



Palmodes rufiventris (Cresson) (p. 325). 



8. Females 9. 



Males : . . 13. 



9. Clypeus slightly rounded anteriorly, with no median emargination or notch. 



Priononyxferrugineum (Fox) (p. 331). 

 Clypeus with a median emargination or notch 10. 



10. Abdomen black or dark brown Priononyx atratum (Lepeletier) (p. 338) . 



Abdomen more or less ferruginous or yellow 11. 



11. Mesonotum rugose Priononyx striatum (Smith) (p. 335). 



Mesonotum not rugose 12. 



12. Prothoracic lobe pubescent (not always sufficient to separate from the 



next Priononyx thomse (Fabricius) (p. 342). 



Prothoracic lobe not pubescent (not always sufficient to separate from the 

 last) Priononyx bifoveolatum ( Taschenberg ) (p. 346). 



13. Clypeus sligiitly rounded anteriorly, with no median emargination or 



notch Priononyx ferrugineum (Fox ) ( p. 33 1 ) . 



Clypeus with a median emargination or notch 14. 



14. Ventral plate of sixth abdominal segment broadly excavated on its posterior 



margin _. Priononyx bifoveolatum (Taschenberg) (p. 346) . 



Ventral plate of sixth abdominal segment not thus excavated 15. 



15. Mesonotum noticeably rugose Priononyx striatum (Smith) (p. 335). 



Mesonotum not noticeably rugose 16. 



16. Abdomen at least partly ferruginous Priononyx thomic (Fabricius) (p. 342). 



Abdomen black or dark brown Priononyx atratum (Lepeletier) (p. 338). 



17. Stigmatal groove rudimentary or absent 18. 



Stigmatal groove present ( Subgenus Proterosjilux) 29. 



18. Third cell not broader on the radial, vein than the distance between the 



second tranverse cubital and second recurrent veins on the cubital vein. 



Proterosphex hicae (Saussure) (p. 365). 



Third cubital cell broader on the radial vein (Subgenus Isodontia) 19. 



19. Mandible with two teeth (anterior tooth sometimes partly divided) 20. 



Mandil)le with three teeth 27. 



20. Petiole l)lack 21. 



Petiole more or less ferruginous or yellow 26. 



