1903.] NATURAL SCIENCES OF PHILADELPHIA. 581 



5. Legs red; metathorax with four pale spots; apex of abdomen 



notched, elrodi, Ckll. 



Legs yellow and black, sometimes with red suffusion, especially 

 toward base, 6. 



6. Apex of abdomen entire; the red on legs preponderating, 



affabilis, Cress. 



Apex of abdomen notched, though sometimes obscurely; legs with 



less red, if any, 7. 



7. Pleura with a large transverse yellow patch, 8. 



Pleura with a smaller yellow mark, below tubercles, ... 9, 



8. The yellow patch almost divided in the middle; scutellum and 



lateral margins of mesothorax yellow, . . sulphurata, Smith. 

 The yellow patch not so ; scutellum with two yellow spots ; meso- 

 thorax all black, rivalis, Cress. 



9. Lateral face-marks not going above level of antennas; small yellow 



spots on scutelliun and metathorax (Europe), . succincta, Panz. 

 Lateral face-marks continued narrowly to top of eye, ... 10. 



10. Eyes conspicuously diverging above; flagellum not denticulate; 



tibise yellow with a black spot behind, .... civilis, Cress. 

 Eyes not or hardly diverging above ; orbits yellow except at sum- 

 mit behind, 11. 



11. Flagellum denticulate beneath; anterior tibise wholly yellow; yel- 



low band on first abdominal segment interrupted, 



luteoloides, Rob. 



Flagellum not or obscurely denticulate beneath; third antennal 



joint little shorter than fourth; anterior tibiae with a black mark 



behind; band on first abdominal segment entire, or reddish in 



middle, luteola, Lep. 



Females. 



1. Third antennal joint longer than fourth; basal nervure hardly or 



not far basad of transverse medial, 2. 



Third and fourth joints subequal, or third shorter than fourth, 6. 



2. Mesothorax red; front red, no yellow spot in front of middle 



ocellus; legs red; basal nervure almost meeting transverse 

 medial, zebrata, Cress. 



Mesothorax red and black, rincta, Say, var. 



Mesothorax black, 3. 



3. Legs red; third submarginal cell narrow, 



vincta, Say (also zebrata, var.). 



Ijegs yellow and black ; a yellow spot in front of middle ocellus ; 



posterior orbits yellow, 4. 



4. Legs red basally ; mesothorax all black, 



xanthophila, Ckll., var. pecosensis, Ckll. 

 Legs not red basally; mesothorax yellow at sides, or with a yel- 

 low spot on each side, 5. 



5. Mesothorax with two yellow stripes on disk, . , edwardsii, Cress. 

 Mesothorax without yellow stripes on disk, . edwardsii, Cress., var. 



