PARASITIC DIPTKKA. 



763 



of gnat. The proboscis is incapable of being withdrawn, is 

 powerful, and bent under the head in a sort of elbow-shape. 



The insects are nearly all 

 prettily coloured, and the present 

 species, which is a native of Brazil, 

 forms no exception to the rule. 

 At a first glance it appears to be 

 only blackish brown, but a closer 

 inspection shows that the abdo- 

 men is clothed with silvery down, 

 while there are gleams as of 

 patches of burnished gold on the 

 legs and forehead. From this 

 latter mark the species receives 

 the name of aurifrons, or " golden 

 fronted." The wings are glossy 

 green, with a gold gloss, and 

 darker towards the upper edge. 



Fig. 507.— Conops aurifrons. 

 {Brown, silver-white, and gold.) 



The fine insect which is given in the accompanying illustra- 



Fig. 508.- Bacuntius vespoides. 



(Black and yellow.) 



tion belongs to the same family as the preceding insect. It is 

 a native of Singapore. 



