80 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.52. 



4. Pubescence on head and thorax, especially on the sides, unusually long and 

 hoary; spur on middle tibia reaching to or beyond the middle point of the 

 metatarsus amoena. 



4. Pubescence not unusually long; spur on middle tibia not reaching middle point 



of metatarsus 5. 



5. Fasciae on tergites sinuate but not greatly attenuated medially; body rather 



slender 6 . 



5. Fasciae on tergites wide laterally and much attenuated medially or reduced to 



widely separated lateral spots; body relatively robust 7. 



6. Fascia on second tergite imperfectly inclosing a pair of dorsal black spots, those 



on third and fourth with pair of anterior emarginations; fasciae yellow. . . .foxi. 



6. Fascia on second tergite sinuate like those on third and fourth; fasciae white. 



spinolae. 



7. Eyes not widely separated and plainly divergent at the clypeus; lateral spots on 



sternites connected by narrow apical lines beutenmulleri. 



7. Eyes widely separated and not divergent at the clypeus; lateral spots on sternites 



not connected 8. 



8. Abdominal markings creamy white; tibiae heavily marked with black; length 



about 16 mm cinerea. 



8. Abdominal markings yellow; tibiae yellow; length 18-20 mm hinei. 



9. Clypeus with a more or less conspicuous pair of basal black spots; fasciae on ter- 



gites white, second usually inclosing a pair of black spots texana. 



9. Clypeus not marked basally with black spots 10. 



10. Sides of thorax and median segment with evident maculations 11. 



10. Sides of thorax and median segment black, rarely with inconspicuous maculation 



on mesothorax 13. 



11. Form large and robust, 17-20 mm; fascia on second tergite inclosing more or less 



perfectly a pair of dorsal black spots connexa. 



11. Form more slender, 14 mm; fascia on second tergite not inclosing black spots. .12. 



12. Fasciae on tergites yellow similans. 



12. Fasciae on tergites white primaaestate. 



13. Fasciae on tergites bright yellow; ultimate tergite with central yellow macula- 



tion cameroni 



13. Fasciae on tergites soiled or greenish white or rarely greenish yellow; ultimate 



tergite black or with white maculation 14. 



14. Pubescence normal; ultimate tergite black spinolae. 



14. Pubescence unusually conspicuous; ultimate tergite with white maculation, 



which in some cases is much obscured comata. 



15. Wings distinctly clouded medially 16. 



15. Wings clear 17. 



16. Clypeus black or marked with black basally; lateral spots on sternites united by 



apical lines melanaspis. 



16. Clypeus yellow; lateral spots on sternites not connected (except rarely on second 



sternite) nubilipennis. 



17. Scutum with no trace of discal marks 18. 



17. Scutum with more or less well developed discal marks .* 22. 



18. Large, 17-20 mm; eyes divergent at clypeus; frons narrow; fasciae on tergites 



continuous 19. 



18. Smaller, 14-16 mm; eyes very slightly divergent at vertex; frons relatively wide; 



fascia on first tergite almost always interrupted 20. 



19. Fasciae on tergites white; that on second never inclosing black spots; clypeus 



usually with basal black mark pruinosa. 



19. Fasciae on tergites yellow; that on second always inclosing pair of black spots; 

 clypeus yellow occidentalis. 



