1925 ] New N emestrinidce from Rhodesia and New Guinea 
7 
with a tuft of long, appressed, white hairs. Venation of the usual 
Prosceca- type; all the longitudinal veins turned upward to end 
before the apex of the wing; no cross-veins between the terminal 
branches of the fourth vein nor between the second and the 
upper branch of the third; fourth posterior cell sessile. 
Length not including ovipositor (to apex of tergite 4), 16.5 
mm; greatest width of abdomen, 8.5 mm; length of proboscis, 
8.5 mm; length of wing, 21 mm; width of wing, 6 mm. 
Male. Very similar to the female in every respect. The 
abdomen is more clove-brown than black, but this is probably 
due to the fact that the greyish bloom is not as well preserved in 
the specimen in hand; the dull, black spots on the middle of the 
abdomen are present, though not quite as distinct as in the 
female. The vertex is just a trifle narrower at the anterior 
ocellus than in the female; but the ocellar triangle is still much 
longer than wide behind. The wings are slightly wider and a 
little more infuscated than in the female; but there is no pro- 
minent thickening of the costa beyond the middle and the 
passage to the nearly hyaline hind portion of the wing is quite 
gradual. The venation is as in the female. 
Total length, 18.5 mm.; greatest width of abdomen, 9 mm.; 
length of proboscis, 9 mm. : length of wing, 23 mm.; width of 
wing, 6.7 mm. 
This species is closely related to Prosceca beckeri Lichtwardt, 
of which it was at first thought to be but a variation. Owing to 
the kindness of Dr. H. Brauns, I was able to examine a male of 
P. beckeri from Montagu Pass, George, Cape Province. It differs 
from the Rhodesian male in several structural peculiarities which, 
however, could not be gathered from published accounts. Thus 
the wing of P. beckeri is, in the male, prominently widened 
beyond the middle, the costa being there considerably thickened 
(length of wing, 21 mm.; width of wing, 6.5 mm.); the wing 
being shaped somewhat like that of the males of Ommatius 
(Asilidse) and of Stenobasipteron (Nemestrinidse). Such a struc- 
ture of the wing is not found in the male of P. rhodesiensis. In 
addition, P. beckeri has the wing much darker in its anterior 
half; the vertex is quite broad, the ocellar tubercle shorter than 
wide, the two posterior ocelli being somewhat farther from each 
