230 bulletin: museum of comparative zoology. 



4. Metanotum with erect hair above Pseudagenia. 



Metanotum without erect hair above Ageniella. 



5. Last joint of hind tarsus without spines beneath Priocnemis. 



Last joint of hind tarsus with distinct spines beneath 6 



6. In the fore wings the first recurrent vein meets the second submarginal 



cell before or at the basal third Pepsis. 



In the fore wings the first recurrent vein meets the second submarginal 

 cell beyond the basal third 7 



7. First recurrent vein meets the second submarginal cell close to the tip 



of that cell Mygnimia. 



First recurrent vein meets the second submarginal cell near the middle. 



Cryptocheilus. 



8. Pronotum longer than the mesonotum, nearly flat above, scarcely arched 



longitudinally, last joint of hind tarsus without spines beneath, tarsus 



I of female without comb of spines 9 



Pronotum shorter than the mesonotum, plainly arched longitudinally. 11 



9. With two submarginal cells Planiceps. 



With three submarginal cells 10 



10. Transverse vein in fore wings sloping backwards; ocelli placed unusually 



low Psorthaspis. 



Transverse vein in fore wings normal, as also the ocelli. . . .Pedinaspis. 



11. Basal abdominal segment with appressed pubescence different from that 



on the other segments Episyron. 



Without such pubescence 12 



12. Metanotum produced angularly at the posterior corners; usually but 



two submarginal cells Aporinellus. 



Metanotum not so produced; three submarginal cells 13 



13. Metanotum transversely striate Ridestus. 



Metanotimi not striate 14 



14. A short impressed line or groove on posterior part of the pronotum . . 15 

 No such line or groove 16 



15. Metanotum distinctly grooved at base; upper margin of clypeus nearly 



evenly curved Arachnophroctonus. 



Metanotum not grooved at base; clypeal suture sinuate or zigzag. 



Batazonus. 



16. Third joint of antennae of female barely if any longer than the first joint, 



spines under last joint of hind tarsus very weak 17 



Third joint of antennae plainly longer than first 18 



17. Metanotum hairy Sophropompilus. 



Metanotum not hairy Nannopompilus. 



18. Third abdominal segment hairy above as well as rest of the body and 



femora Arachnophila (Alaska). 



Third segment not hairy above 19 



19. No spines under last joint of the hind nor front tarsi, clypeus not emargi- 



nate, third submarginal cell not petiolate 20 



Distinct spines under last joint of the hind tarsi; no malar space 22 



