366 PERCY SLADEN TRUST EXPEDITION 
Thorax. Shiny black with sparse yellow pollen, covered with fine bristles except 
just at base. Stout last d.c., very fine prescut. A stout bristle on p. a. callus, other 
bristles destroyed by pinning. Scutellum very minutely 
; rugulose, two moderate basal, two long terminal bristles, 
crossed at tip. Wings, as Fig. 45, moderately strong ciliation 
; in first section costa, there are none of the strongish black 
bristles visible on costa to end second vein, but the stout 
Fig. 45. Desmometopa ciliation is uniform in character up to the fourth vein. Halters 
approwimatonervis,n. sp. x30. brown, a little darker on tip. All the legs brownish black with 
the tarsi paler tawny. 
Abdomen. Shiny black, with brownish tone in parts, covered with black hairs, the 
last segment is nearly twice as long as the previous one; the next are roughly equal in 
length. 
Size, about 1°4 mm.; wing, about 1'4 mm. 
Locality. Seychelles. Mahé: Cascade Estate, at or above 800 feet. 
Manpiza Fallen, Dipt. Suec., Oscinid., 8 (1820). 
63. Madiza albipennis, n. sp. (Fig. 46 and Plate 21, fig. 59). 
This is an almost entirely shining black insect with markedly milky wings. 
Head. Top view :—frons black and shining, narrowest about opposite front ocellus, 
widening just perceptibly in front: it is paler just over the forehead. The first of the 
front f. 0. is close to the forehead, the second just in front of the hind pair: between are 
three small bristles; both converge a little. The narrow eye-margins extend to the 
front of the hind pair of f. 0., they are more shining than the rest in side illumination, as 
is an evident ocellar triangle. The hind f. o. are fairly close, they diverge over eyes, have 
“a small bristle between, and then two or three small ones up to thei. v.: these converge 
somewhat; o. v. bent out, a small bristle between the i. and o. v. bent inwards: this is 
really the last of the regular post-orb. row. P. v. almost exactly on vertex, pointing back 
and sub-parallel. Oc. inserted rather nearer front ocellus than side one: a few small 
bristles on ocellar area; four in a row over the forehead, a small pair on middle of frons. 
Front view :—antenne widely separated at the base by an orange triangular projection of 
the lunular arch which nearly meets a more obtuse orange upward projection of the lower 
lip just about the level of the end of the antenna. The face has a roughly circular 
outline almost cut into two deep pits by these two projections. Side view (Plate 21, 
fie. 59) :—second antennal joint with a spine; third almost quite spherical, blackish with 
pale silky pollen, arista slender, just perceptibly pubescent under a high power (x50). A 
large upper vibrissa is apparently present, but its end is broken off, below it a smaller 
one: jowl-margin with fine bristles. The jowls are very deep, shining black, and in good 
light can be seen to be minutely striate longitudinally. Hind angle of jowl with a few 
extra long bristles. When looked at from below the mouth is seen to be orange. Palpi 
rather flattened and strap-like: rather orange dorsally, black below, sparsely bristled at 
end and below. Tongue long and horny with a pointed tip. 
