Genus Megarhinus. 239 
tarsal joints of the hind pair white; ungues of the hind pair 
equal and simple. 
Wings with brown veins and with a curious faint reduplica¬ 
tion of the fifth long vein at the border; scales along the upper 
border blue; first sub-marginal cell very small ; supernumerary 
cross-vein a long way nearer the apex of the wing than the mid 
cross-vein; posterior cross-vein long, sloping to the base of the 
wing, arising nearer the apex than the former; border much 
bent in at the junction of the fifth long vein with it; halteres 
with ochraceous stem and brown knob. 
Length .—8 to 10 mm. 
£ . Head like the 9 5 but the median scales look dark when 
facing the light, similar to the 9 when turned away from it; 
basal joint of the antennae black with grey fomentum, second 
joint large, about as long as the four following joints, densely 
covered with blue scales ; remainder of the antennae brown, with 
rich brown plumes; palpi bright metallic blue and purple, the 
third joint a little longer than the second and fourth, the fourth 
thick with three spines on the inner and two on the outer side, 
apical joint longer than the two preceding, tapering to a point, 
black. 
Thorax as in the 9 5 but without the median blue line and 
with the mid lobe of the scutellum peacock blue instead of deep 
purple; the first segment of the abdomen is also peacock blue; 
the remainder deep steel blue; the fourth to seventh segments 
have apical yellow bands and also the apical segment; genitalia 
(denuded) brown. 
Legs the same colour as in the 9 1 fore legs without white 
tarsi ; in the hind legs the third and fourth tarsals'are white on 
one side only; fore ungues unequal, the larger uniserrated, the 
smaller simple ; hind ungues equal and simple. 
Wings with the supernumerary cross-vein much nearer the 
mid than in the 9 and niuch longer; the posterior cross-vein 
nearer the base of the wing; the fold of the sixth long vein at 
the border more marked than in the 9 • 
Length .—9 * 5 mm. (palpi 8 mm.). 
Habitat .—Bogota (Bigot); Brazil (Macq.), Brazil (Bigot). 
Observations .—Described from a $ and 9 in the Hope 
Museum, Oxford. I have also examined specimens so named in 
Bigot’s collection. I believe all three of his specimens were 
Macquart’s. 
