40 Syrphidae. 



9. Epistoma wifh a central knob and generally not 



specially produced at the front mouth edge 10. 



— Epistoma without central knob but its lower part 

 rather produced, sometimes bec-like 25. 



10. Hind femora simple, not spinose beneath 11. 



— Hind femora thickened, spinose beneath 35. Myiolepta. 



(belongs to Milesiinae). 



11. Abdomen not specially constricted about the base .... 12. 



— Abdomen much or somewhat narrow and long, 

 distinctly constricted about the base 24. 



12. Epistoma and scutellum entirely black or æneous, 



only epistoma more or less pruinose 13. 



— Epistoma yellow or partly so, in rare cases only 

 slightly; scutellum yellow or brownish, often trans- 

 lucent and at all events a little pale on the disc or 



at apex 17. 



13. Wings a little shorter than the flattened, a little 

 club-shaped abdomen ; this latter has extended reddish 



markings on the middle or only one pair of spots 10. Pyrophaena. /.Lj-. 



— Wings not shorter than abdomen and this not club- 

 shaped or specially flattened; it has generally three 



or four pairs of yellow (or hoary) spots 14. 



14. In the male front tibiæ or tarsi or both dilated, in ■ 

 the female front tarsi relatively broad; abdominal I 

 spots in the female distinct, not with the outer 



margin sloping inwards towards the end (disting- 



uishing from Melanostoma) 9. Platychirus. j'fc) 



— Front tibiæ and tarsi simple in both sexes 15. 



15. Abdomen narrow, with parallel sides 16. 



— Abdomen broad, flat and ovate, with large spots, 

 especially in the male 12. Xanthandrus. •i- 5^ 



16. Eyes a little hairy; abdomen in the female without 



markings 13. Melangyna. ^^X 



— Eyes bare; abdomen with pairs of spots which in 

 the female have the outer margin sloping inwards 

 towards the end, or (ambiguum) with inconspicuous 



metallic spots 11. Melanostoma. i.'lu' 



1 7. Thorax with bright yellow side-lines and pleura with 

 yellow spots 18. 



— Thorax without or with inconspicuous pale side- 

 lines; pleura without yellow spots 19. 



18. Abdomen narrow, elongate or clubbed, fifth segment 

 in the male long, its hind margin not quite sym- 

 metricai 20. Sphaerophoria.;i J \ 



— Abdomen somewhat broad and flat, fifth segment in 



the male small 21 . Xanthogramma.^ J\ 



19. Abdomen with sharply defined yellow bands or yel- i 

 low or whitish pairs of spots 20. 



— Abdomen without sharply defined yellow bands or 

 spots, with only one basal band, or if more pairs 



