‘a new Genus and eight new Species of Diptera. 513 
Moor Plantation, near Ibadan, 8. Nigeria, Dec. 23, 1917, 
to Jan. 26, 1918, and sent to illustrate Farquharson’s 
observations on Milichia published in Proc. Ent. Soc., 
1918, pp. XXxill, XXXIV, xl, where it is shown that these 
flies solicit and receive regurgitated food from ants in 
the track running up the trunk of “ Cremastogaster-ant- 
trees.’ —E.B.P.] j 
3. M. prosaetes, sp.n. Plate XVII, figs. 2 and 3. 
Smaller and more shining than the previous two species. 
Abdomen distinctly shining and without silvery patches. 
Frons much narrower in male. Vibrissal angle more 
projecting. 
3. Frons only about twice as wide as third antennal joint is 
deep, dull brown, but varying from almost black to dull greyish 
brown according to the point of view. Frontal lunule with a pair 
of distinct bristles. Face very short, no longer than third antennal 
joint is deep. Both face and frontal Iunule appearing silvery from 
some points of view. Vibrissal angle more projecting and the 
cheeks between face and eyes wider. A single vibrissa followed by 
a rather widely spaced row of short bristly hairs towards back of 
head. Palpi dark brown or reddish brown and pubescent, dilated 
leaf-like, but of a more even width throughout instead of being 
triangular as in the previous species. The long, very pointed, slightly 
hairy paraglossae of proboscis may project straight out between palpi, 
or be bent back and point towards prothoracic sternum. Antennae 
with third joint reddish brown, arista shorter than in the previous 
species and only microscopically pubescent. Thorax rather shining, 
dark brownish black; pleurae and hind part of disc in front of 
scutellum dusted greyish. Chaetotaxy as in argyratoides except 
that middle bristle of the three supra-alar bristles is not in a line 
with other two but placed rather higher up on disc. Abdomen 
very distinctly shining and blacker than thorax, the black hairs 
short and not very numerous. ‘Tergites extremely narrow on first 
three segments, widening out into a triangle on fourth, and still 
wider on fifth, segment. Legs with the knee joints very narrowly, 
and the joints of coxae and trochanters indistinctly yellowish, 
hind femora at base with a long, fine, postero-ventral, bristly hair. 
Wings short and rather broad, faintly tinged with brown and dis- 
tinctly brownish along the costa from humeral cross-vein to end of 
subcostal vein. Cross-vein closing discal cell not so sloping as in 
proectes; last portion of discal vein about two-thirds length of 
