LAMB—DIPTERA: HETERONEURIDA, ORTALIDA, TRYPETIDA, SEPSIDM, ETC. 317 
outer v.b. ‘The p. v. parallel and rather bent backwards, inserted on the sloping back 
of vertex, the distance between each and the next 1.v.is the same. Oc. fine, subparallel, 
inserted each side of the large front ocellus. Front view :—face brown, same width 
as frons to just below 2nd antennal joint, then widening uniformly to jowls. The 
lunular crescentic furrow continued round and demarcating eye-margin from face. A 
very shallow broad triangular keel forms two shallow fovee. Antenne almost touching 
at base, divergent. Side view (Plate 19, fig. 6) :—antennze orange, the 2nd joint is very 
bristly inside, outside smooth, neat bordering row of bristles below, a spine about midway 
above ; 8rd joint long, straight upper and curved lower profile; arista with pale pubescent 
lower joints, darker flagellum with short hairs all round in no definite rows. The 
narrow front jowls with short bristle below, orange; hind ones deeper, universally 
bristly with one long spine: hind head below black and bristly. Palpi flattened 
laterally, very bristly below, orange: tongue the same. The shining clypeus is visible. 
Thorax. Dorsum, pleura, scutellum and metanotum all shming black, the dorsum 
covered with fine hairs: the chetotaxy as Acidia cognita though possibly not relatively 
so strongly developed: there is a pair of d.c. rather forward, being roughly in a line 
with wings; long prescut., h., n. p., prescut., a large post-a.; the pleura has fine sparse 
bristles, but the pinning renders the macrochetes doubtful though a sterno-pl. can be 
seen. Scutellum a blunt shallow triangle, the terminal bristles crossed at tip, the large 
side pair ending off nearly level with them. 
Wings, as Fig. 10, with brown-black coloured marks, Ist and 3rd veins bristly above. 
Halters with black knobs and orange stalks. 
Legs. All the coxee and femora black ; the rest yellow-orange, except that the basal 
half of the hind tibia is blackened. Front femora with the two hind rows of spines 
and the long lower row: middle with long spinous hairs; hind with similar hairs, 
more conspicuous below at base, and one or two at tip on top. Hind tibie with 
longish spiny hairs, a somewhat regular row dorsally. 
Abdomen. Black, pointed, with adpressed hairs and long marginal bristles, 
ovipositor not extruded. 
Size, 4mm.; wing, 3? mm. 
Locality. Seychelles. Silhouette: plateau of Mare aux Cochons, IX. 1908. 
18. Acidia(?) ocellata, n. sp. (Fig. 11 and Plate 19, figs. 7, 8). 
There is a single specimen of a fine Trypetid from Marie Anne Island which does 
not seem to agree well in its characters with any of the well-known genera. Its general 
affinities seem nearest Acidia, and hence it is provisionally referred to that genus 
pending a revision of the whole family. The description will therefore be given in full. 
Head. Eyes under high power with a very few fine scattered hairs: frons 
widening a little from back to front. Top view :—frons, vertex (as well as hind head) 
entirely pale orange, dull except for the ocellar area and the upper and lower eye- 
margins, which are shining: the latter have about 3 irregular rows of fine bristles. 
On them stand the three lower crossed f. 0. pairs, the middle one being crossed almost 
41—2 
