320 PERCY SLADEN TRUST EXPEDITION 
The oc. are very long and arched, div. and inserted one each side of front ocellus. There 
are practically no tiny bristles on the head. Front view :—face yellowish-white, no 
foveze or keel ; antenne orange, the overlap of 2nd joint swollen inside, the 3rd joint long, 
oval and rounded at tip, the arista with pale base and darker flagellum, the latter 
just perceptibly pubescent. The antenne are just separated at the base by a narrow 
projection from the lunule over the antennz. Side view (Plate 19, fig. 9) :—mouth margin 
projecting somewhat, the sides bristly as is edge of jowls and the swollen hind jowls; 
the latter have a long bristle on them. The post-orb. row can be seen to have small 
bristles between the large ones. Palpi flattened, pale yellow and hairy. 
Thorax. Ground colour dark and covered with grey pollen in a good specimen, and 
also dorsally with tiny white bristles, which are, however, long just over the scutellum, 
cheetotaxy normal, being all very long: two d. c., one just behind cross suture, one 
a little further than half-way from front pair to end of thorax. A very stout bristle 
and a clump of small stubbly ones on the orange humeri, large and small h., presut., 
two s.a., one long and smaller ones by the mesopl. suture, one st. pl.; the pleurz all with 
bristly hairs except in front. The bare pollinated scutellum has a rather small 
terminal pair, crossed half-way, and excessively long parallel side pair. The wings 
are maculated as in Fig. 12, the darkening being bright brown, paler towards the 
hind margin. Halters yellow with orange stalks. Legs all orange; the lower row 
of bristles on front femora very stout and long. 
Abdomen. Brown, slightly shining, covered with pale hairs. The ante-penultimate 
segment in the male is nearly as long as the three previous ones: in top view it is 
bordered by some 5 or 6 long pale bristles. The hypopygium below the last segment 
is shining chestnut brown. The terminal segments of the female are shining black 
as is the long dorsally flattened ovipositor sheath, which is longer than the rest of 
the abdomen. 
Size, 35 mm.; wing, 3 mm. 
Locality. Aldabra, 1908 (Fryer). 
Ruaspocuata de Meijere, Bydr. t. d. Dierkunde, xvii. (1904), p. 109. 
20. Rhabdocheta spinosa, n. sp. (Fig. 13 and Plate 19, fig. 10). 
A considerable number of an insect occurred which seems to fit in best with de Meijere’s 
genus, though it will be seen that the characters do not agree absolutely with his 
definition of the genus. 
Head. Eyes bare. Frons about as broad as long, nearly parallel-sided, the ridge 
of the vertex from eye to eye very sharp; orange in front, greyish-yellow round 
ocellar area and eye-margins: lunular are with flattish ridge and linearly darkened : 
ocellar spot black. The bristles are of two characters, (a) long darkish ones coming 
gradually to a point (viz. the two main front f. o. and the inner y.): the others (@) are 
white, long or short, but roughly cylindrical up to the tip where they attenuate much 
more suddenly, or are even greatest in diameter about half-way. There are two long 
