Explanation of Plates. 573 



Fig. 18. BUs calehs ?, Dec. 16,"-1900. 



19. Melittia sp. „ „ Mimic of the above. 



Figs. 20 to 29 and 31 are insects with dark-blue or blackish 

 wings and yellow heads. Where the anterior yellow is 

 most developed (as in Fig. 25) the group merges into the 

 preceding one ; where it is least, the convergence is 

 towards the blue-winged group shown on Plates XX 

 and XXI. 



20. Punnyilus marshaUl ? , Oct. 1899. 



21. „ cZic/tro//A- t^, Jan. 1900. 



22. „ „ ?, Oct. 1899. 



23. „ lascivus $, June 1900. 



24. ,, anticns $, Jan. 1900. 



25. Saliiis tamisieri $, Feb. 1899. 



2G. Tachysphex flactuatui 5, June 1900. 



27. Bromophila caffra, Dm. 1899. 



28. Jonthodes sculpt ilis, Nov. 1898 to Jan. 1899. 



29. Eletica rufa ^, Nov. 1898 to Jan. 1899. 



Figs. 30, 32, and 33 are blue- or black-winged insects with 

 yellow-banded legs which are very conspicuous during 

 flight. 



30. LitopHu dispar, Feb. 1899. 



31. Iphiaulax ruber 5 , Oct. 1900. 



32. Osprynchotusjiavipes ? , Jan. 1900. 



33. Pirates xneicoUis, Dec. 1900. 



Figs. 34 to 36 are black insects with narrow yellow bauds 

 and clear wings. 



34. Pompihcs festiims $ , Jan. 1899. 



35. Myzine capitata ^ „ „ 



36. Metopius discolor $ „ „ 



Two flies with their model a Megaclule bee. 



37. Meyachile apiformis ^ , Jan. 1899. 



38. Eumerns sp. nov. ? ,, „ 



39. Laxenecera mollis, Mar. 1900. • 

 The following figures represent a Syrphid fly which closely 



mimics a common social wasp. 



40. Polistes marginalis ^ , Dec. 1898. 



41. Ceria gambiana „ „ 



