132 



E. T. CRESSON. 



Two apical segments each with a pale spot; no pale orbital lines. 



Postpetiole broadly dilated ; thorax, except scutellum, entirely black ; 



wings smoky 38. biinoiiibris. 



Postpetiole narrow; collar above, line in front and beneath tegnlse 



white; wings clear 40. brcviciiictor. 



Posterior legs black or blue, their tibise marked with white or yellow. 



Mesothorax brown-ferruginous 11. ccntrator. 



Mesothorax black. 

 Coxal scopa distinct. 

 Apex of abdomen immaculate. 



Scutellutn entirely black 16. corviniis. 



Scutellum black, white only at sides 25. navus. 



Scutellum white. 



Coxal scopa very large, covering nearly their entire under surface ; 



posterior tibise with white line behind near base 46. sagllS. 



Coxal scopa narrow, linear; posterior tibife with an entire white au- 



nulus near base 47. proniptus. 



Apex of abdomen with a white spot 43. stygicttS. 



Coxal scopa wanting. 



Apex of abdomen immaculate. 

 Scutellum black. 



Femora incrassate; pale orbital lines distinct in front above the 



antennte 4;-,. pravu!^. 



Femora slender; pale orbital lines wanting 44. pilosulus. 



Scutellum pale. 



Metathorax with round white spot on each flank 57. otioi^us. 



Metathorax immaculate 56. uiiilasciiitoriiis. 



Apex of abdomen with one or more pale spots 42. atrox. 



Posterior legs black; coxse, femora and tibise marked and banded with white; 



abdomen steel-blue '. 24. piilclier. 



Posterior legs black; base of tibise and the tarsi ferruginous; apex of abdomen 



with two pale spots 62. gcstuosus. 



Posterior legs black, their femora ferruginous 65. seinilaivis. 



Posterior legs ferruginous. 



Apex of abdomen immaculate 67. pcdalis. 



Apex of abdomen more or less white 69. Itclvipes. 



Section II. — Abdomen black, marked with white or r/elloio spots or bands, and some- 

 times varied with ferruginous. 



Second segment only with two white spots 70. biot'iilatus. 



Second segment only with white or yellowish band. 



Coxal scopa distinct 71. unciiiattis. 



Coxal scopa wanting 72. f oralis. 



Second and third segments each with a yellowish band. 

 Coxal scopa distinct; two white spots at tip of abdomen.. ..76. calitergns. 

 Coxal scopa wanting. 



Apex of abdomen immaculate 7.3. bixoiiatiis. 



Apex of abdomen with white spots 72. feraliM. var. 



Second, and often third segments with a yellowish band at tip, apical segments 

 ferruginous, also mesothorax and generally the metathorax; fe- 

 mora black 101. subdolus. 



