128 Clarence E. Mickel 
10. 
Fp Be 
12. 
13. 
14. 
15. 
16. 
17. 
18. 
10. 
20. 
First segment black, sometimes with a spot or band of yellow..... 9 
Face. wholly svellow? .ciccncs cctiseasiooe et ene ene eee finitima 
Face with a large black spot each side between clypeus and base of 
the mandinles\ <7 A. 2c susie hese ate atoms eee finitima nigroris 
No band on the second tergite, which is wholly black; a band on the 
first tergite;) ho ‘marks on-metanotumy <.osi ese. -s es sees insolita 
A: band. of yellow on sécond térpite |... 00.2) ee ace II 
Mesepisterna dentate} antennae situated high above the clypeus, the 
last joint thick;-bands on tergites subequal in width ....... compar 
Miesepisterna: not) toothed): cia eases aetincco ee ee eee 12 
Hind femora black, except at tips; metanotum black; small, coarsely 
PUNCTALEY, SPECIES cic sae ee aek tte ee eee kennicotti 
Eide femora «mostly; patel sr. <cictcuienae ero cere eine nee ere Pret! 
Metanotumr ‘black: gc. ottiensscictentos o Soee cereale cio aie eee 14 
Scutellum and metanotum marked with yellow ................... 15 
Propodeum without yellow stripes; first tergite immaculate (some- 
times both scutellum and metanotum black) .......... flavofasciata 
Propodeum with yellow stripes; first tergite with a yellow band; bands 
an: tergites subequalim width... 225.02 yeni wee eae femur-rubrum 
Large species, 22-25 mm.; red, black and yellow ............ frontata 
Smaller. species, 10-15 mm.; black and yellow <s5-.ijuc ce oe ole nee 16 
Propodeum not marked with yellow; stigma dark; clypeus acutely 
produced, below in, thie tmiddle: <eseyacvacts oeicesneeitiereetoe compacta 
Propodeum with lateral yellow spots; stigma yellowish; yellow mark 
on) clypeus acuminate, DElow, uesce esheets ok eet ee pleuralis 
Clypeus flat, broadly truncate in front; propodeum and first tergite 
marked with yellow; enclosure striate at the a: .occipitomaculata 
Clypeus cotivex, no transverse impression .....6. oss as dese sedes 18 
Large species, 13-15 mm.; clypeus truncate apically; first tergite of 
abdomen spotted; bands on remaining tergites subequal...... sexta 
Smaller species, 9-12 mm.; clypeus usually tridentate ............ 19 
Spots on first tergite; enclosure striate all over; ornaments white; 
venter with larce spotsfotm bands... cmpeact pena nigrescens 
Rarely spots on first tergite; enclosure striate all over, last ventral 
Plate, funcate at, thes tip. stecswisenc nome caersin ears eee eee eee 20 
Enclosure finely evenly striate; abdomen very slender, first segment 
narrow; usually but four or five teeth above on hind tibiae, 
imitatoria 
Enclosure more coarsely striate; abdomen broader, more coarsely 
punctate; six to eight teeth above on hind tibiae .......... clypeata 
Cerceris bicornuta Guerin. 
1845. Cerceris bicornuta Guerin, Icon. Reg. Anim., p. 443. 
1912. Cerceris bicornuta Banks, Ann. Ent. Soc. Amer., V, p. 16. 
446 
