274 Mr. C. H. T. Townsend on Di'/dera 



3. Costal half of wings fuscous, without yellow; 



pollen of abdomen divided by a median 



stripe • • • '^• 



Nearly all of costal half taken up with 

 yellow, leaving but little fuscous ; no 

 median abdominal stripe dividing the 



pollen hisirio, 



var. indioisa, var. n. 



4. Segments four and five each with an inter- 



rupted golden-yellow pollinose fascia, 



third segment without histrio, Walk. 



Typical form. 

 Segments three, four, and five, and some- 

 times also the anal, with such fascia .... histrio, 



vai". trifasciata, Lw. 

 6. Wings with yellow or milky-white ; if 

 with no white, at least with a distinct 



trace of yellow near costa 6. 



Wings wholly black except inner border, 

 without yellow ; abdomen mostly reddish 

 yellow, sometimes dark at tip ; meso- 

 scutum with postsutural goldeu markings. pe7inipes, 



yav. pilipes, Fabr. 



6. Wings milky -radiate on a yellow or fuscous 



background (formosa and vars.) 8. 



Wings not so 7. 



7. Wings with a more or less distinct yellow 



patch on costal portion, never approaching 

 tip of wing ; abdomen reddish yellow, 



with no blackish unless at tip pennipes, Fabr. 



Typical form. 

 Wings yellow on costal portion, nearly 

 approaching tip, the yellow bordered 

 behind by fuscous, which takes up the 

 middle of the wing lengthwise; abdomen 

 yellow with black on base, continued 

 posteriorly in a median stripe subalipes, Towns. 



8. Mesoscutum with postsutural golden -pol- 



linose markings 9. 



Mesoscutum without such markings 10. 



9. Milky radiations of wings very conspicuous 



with the yellow less apparent, abdomen 

 rather strongly purplish ; hind femora 

 strongly ciliate on apical half : robust 



form formosa, 



var. radiata, Lw. 

 Wings conspicuously and broadly yellow, 

 with the milky radiations less apparent; 

 abdomen orange -yellow, more or less 



dark on median line and tip formosa, 



var. inconstans, Wd, 

 10. Wings with the milky radiations on a 

 fuscous ground, with little if any yellow ; 

 hind femora ciliate apically, abdomen 



reddish shading to purplish formosa, Wd. 



Typical form. 

 Wings with a yellow patch, hind femora 



