36 E. T. CRESSON. 



Posterior femora obscure reddish, varied with blackish, inner side mostly 



reddish 5. rufofcmorata. 



Body black, more or less marked with white or yellowish : 

 Markings of thorax very small and indistinct; the posterior femora with a 

 single pale dot on upper outer middle ; the abdomen entirely 



black 6. delumbis. 



Markings of thorax small, but distinct: 

 Posterior femora with irregular whitish markings at apex, varied with pale 

 brown : 



Abdomen black, with two or four white spots at base 7. torvina. 



Abdomen black, with numerous lateral white spots 8. flavopictu. 



Abdomen reddish at base and sides, with numerous pale spots..9. delira. 



Posterior femora with a broad, irregular, whitish band on the apical 



half; the abdomen reddish at base and sides, with six white 



spots 10. mendica. 



Posterior femora with a broad basal margin and dot at apex above, pale yel- 

 low ; prothorax and scutellum each with two small yellowish spots ; 



abdomen black 11. subobsoleta. 



Posterior femora with a short yellowish stripe above near apex and a dot 



beneath; abdomen mostly yellow, petiole black 12. Toluoa. 



Posterior femora margined above and at base beneath with yellowish, and 

 armed beneath with only six teeth ; apical half of the abdomen 



yellowish 13. mexicana. 



Posterior femora pale fulvo-ferruginous, with three yellow spots at apex; 

 abdomen pale sanguineous, with four pale yellowish spots at 



base 14. sanguineiveiitris. 



Markings of thorax large, white, yellow or reddish : 



Posterior femora black, margined above and at base beneath with whitish, 

 also a white spot beneath near apex : 

 Scutellum black, with two large ovate white spots ; posterior tibire with a 



small pale spot on outer side near base 15. bio<'iilul;i. 



Scutellum yellow, except extreme base and apex ; posterior tibise with a 



broad yellow annulus 16. let'ta. 



Posterior femora black, with basal margin beneath, a large spot at apex 

 above, and a small spot near apex beneath, white; the posterior 

 coxae above and most of abdomen red; the scutellum mostly 



white 19. lauta. 



Posterior femora yellow, with a large, median black spot, generally con- 

 fluent with a spot at apex; the scutellum almost entirely yel- 

 low; the abdomen fulvous, with a yellow subinterrupted me- 

 dian band 17. ambigua. 



Posterior femora yellow, with a large irregular black mark near middle and 



a small black spot on extreme tip; scutellum with two large yellow 



spots ; abdomen black, with a median yellow band... 18. arcana. 



Posterior femora yellow, irregularly black at base and along inferior edge ; 



the scutellum with a large, longitudinally ovate, black, central 



spot 20. Nortonii. 



Posterior femora yellow, with a slender, subfusiform, oblique, black stripe 

 near apex; scutellum with a large, median, cuneiform, black spot; 

 abdomen banded with yellow 21. coxalis. 



