12 University of Michigan 



tending from the wings to the anterior edge of the prothorax. 

 Antenna long, the second joint about .3 mm., the third joint nearly 



three times as long, the ratio about 1.5 :4 flavovit latum. 



a'. Thorax not sharply patterned as above ; humeral or antehumeral 

 stripe if present narrower and obscure, not definitely a part of the 

 prothoracic pattern. Antenna shorter, the second joint about .2 mm., 

 the third joint from two to nearly three times as long as the second. 

 b\ Cubito-anal cross-vein proximal to the arculus a distance equal 

 to or less than the length of the latter. A distinct dark post- 

 humeral stripe. 

 c\ Basal dark area on dorsum of segment 9 divided in the median 



line by pale nearly or quite to the base of the segment 



triaiigulare. 



c^ Basal dark area on dorsum of segment 9 not divided by pale 



in the median line ictericum. 



b^ Cubito-anal cross-vein proximal to the arculus a distance greater 

 than the length of the latter. Dark color on dorsum of segment 9 

 not divided b}'^ pale in the median line. 



c\ No dark posthumeral stripe auraniiacum. 



c'. A distinct dark posthumeral stripe. 



d\ Posthumeral stripe brown, the same color as the dorsal 

 thoracic brown stripes. Hind lobe of prothorax narrow, 

 ^ rounded and high — a female in Hagen's collection labelled 

 aurantlacuiu." 

 d'. Posthumeral stripe black, darker than the thoracic dorsum. 

 Hind lobe of prothorax similar to aurantiacum, broad, 

 winged and with a median dark area ochracenm. 



Key to Males of Group j 



a\ Abdomen above predominantly pale, no segment as much as one- 

 fourth definitely black; segments i and 2 without any definite black 

 areas; 8-10 largely or entirely pale or obscure. 

 b\ Abdomen brilliant red, black inconspicuous or wanting. 



c\ Face black ; abdomen without black eryfhrogastrum. 



c". Face bright light yellow; abdomen with some segments nar- 

 rowly apically black albifrons. 



bl Abdomen reddish yellow or flesh to almost red, segments 3-6 

 with distinct apical black areas ; face yellow. 

 c\ Abdomen 47-51.5 mm. long; usually three postquadrangular 

 cells tricellulare. 



« By the form of the hind lobe of the prothorax certain known species are ex- 

 cluded, and the species may be dorsale (of which the female has not been de- 

 scribed), cinnamomeutn (unless this is a synonym of aurantiacum, as de Selys 

 has stated; the female of cinnamomeutn is not described), or maciletitum (of 

 which only the teneral female is described). See under aurantiacum in the text. 



