LAMB—DIPTERA: HETERONEURIDA, ORTALIDAL, TRYPETIDA, SEPSIDA, ETC. 331 
Abdomen. 2nd segment whitish-yellow with black margins wider at sides ; 
3rd black with two faintly defined transverse elongate marks each side of the centre 
line; 4th black with two large roughly semicircular pale spots with their diameters 
on the base of the segment, distal margin narrow and pale; 5th similar but with 
smaller elongate spots; 6th black with a central pale line which is widest proximally; 
genital segments pale. In side view the whole of the abdomen appears black. The 
belly is pale on the centre Ime. There is a small amount of variation in the exact 
shape of the spots and amount of orange on the 38rd segment. 
Size, about 24 mm.; wing, about 24 mm. 
Localities. Seychelles. Mahé: ‘Cascade Estate, at or above 800 feet, 1908—9. 
Praslin : Cotes d’Or Estate, XI. 1908. 
28. Drosophila nigerrima, n. sp. (Fig. 18 and Plate 19, fig. 17). 
This is close to the last in many structural points, but is remarkable for its 
almost entirely black colour and its coriaceous texture. 
Head. Eyes bare, colour entirely black, except for the brownish antennz and 
lighter face. Top view :—frons dull black and finely granulate, except for the ocellar area, 
a line from it to forehead, and the broad eye-margins, which are shining; the frons 
narrows slightly from behind to the front ; sub-parallel front f o., slightly divergent 
back f. 0., the usual fine row of bristles continuing the latter to forehead, the first 
(between the f. 0.) being the longest of them; strongly convergent 1. v. nearly touching 
at tips, divergent o. v.; p. v. directed backwards, nearly meeting at the tips, inserted 
just below the vertex; divergent oc. on the ocellar triangle. Front view :—antennee 
just separated at base by the beginning of the facial keel which widens downwards 
in a uniform manner to about three-fifths of the depth of face. The face is all dark 
except that the snout formed by the keel is paler than the rest especially on its 
side surfaces. The black prelabrum is very evident. The palpi are included, so cannot 
be described. Side view (Plate 19, fig. 17):—the 3rd antennal joimt is brownish and 
pubescent; 2nd joint with a well marked spine on tip and a much smaller curved one 
in front; arista with 4 top, 2 bottom, one terminal ray: some 3 or 4 sparse rays of 
the inner row are visible. Convergent vibrissee with a following row of fine bristles ; 
hind jowls with a few longer bristles. The post-orb. row is present, but the bristles are 
not quite so evident as in most cases. 
Thorax entirely black, slightly shining, dorsum finely punctulate and uniformly 
covered with very short adpressed hairs: the last pair of d. ¢., two smallish h., n. p., 
small presut., p. a., one larger and one or two smaller bristles over the wing, no acr. ; 
pleural bristling not visible owing to the position of the single specimen. Scutellum 
more velvety black, rounded in outline and profile ; crossed terminal, and two smaller 
side bristles, nearer the terminal than base. 
Wings as Fig. 18, smoky with dark-orange veins; costal break well marked, 
black, spiny, and turned up perpendicular to the wing-plane. Costa to 4th. Halters 
dull brown-orange with suffused tips. Legs black except for somewhat orange knees 
SECOND SERIES—ZOOLOGY, VOL. XVI. 43 
