63O CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



spines beneath; fore tarsi of female without comb; no 



erect hair on metanotum 2 



Pronotum shorter than mesonotum, plainly arched longitudi- 

 nally 3 



2. With two submarginal cells Planiceps 



With three submarginal cells Pedinaspis 



3. Basal abdominal segment with appressed pubescence, differ- 



ent from that on following segments; pronotum with pos- 

 terior margin membranous- and often white; third cell as 



broad as long Episyron p. 631 



Basal segment of abdomen not with pubescence different from 

 following segments 4 



4. No erect hair on metanotum above, only pubescence 5 



Erect hair on metanotum above 9 



5. Metanotum produced angularly at posterior corners; but two 



submarginal cells Aporinellus p. 631 



Metanotum not produced angularly behind; usually three 

 submarginal cells 6 



6. Metanotum transversely striate; marginal cell as long as 



distance to tip; third cell long, and wide above Ridestus 



Metanotum not transversely striate 7 



7. Marginal cell short, subtriangular, much more than its length 



from tip of wing; third submarginal cell much narrowed, 

 triangular, or petiolate above; basal vein usually a little 



before the transverse median Pompiloides p. 631 



Marginal cell long, hardly its length from tip of wing; third 

 submarginal cell wide above; basal vein of fore wings inter- 

 stitial with the transverse median 8 



8. Hind tarsi spined, apical joint spined beneath; propodeal 



spiracle opening posteriorly; abdomen cylindrical, first seg- 

 ment subequal in length with second, not much narrowed 



anteriorly; large, ferruginous Arachnophroctonus p. 632 



Hind tarsi not, or but feebly, spined, apical joint without 

 spines; propodeal spiracle opening sublaterally; abdomen 

 depressed, first segment longer than second and narrower 



anteriorly; slender black with yellow marks 



Sericopompilus p. 632 



9. A short longitudinal impressed line or groove on posterior 



part of pronotum; head nearly or fully as broad as long; 



not wholly black I0 



No such impressed line or groove on pronotum; often wholly 



black Psammochares p. 632 



10. Metanotum distinctly grooved at base; upper margin of 



clypeus nearly evenly convex Arachnophroctonus p. .632 



Metanotum not grooved at base; upper margin of clypeus 



sinuate or zigzag Batazonus 



