LAMB—DIPTERA: HETERONEURIDA, ORTALIDA, TRYPETIDA, SEPSIDA, ETC. 345 
front f. 0. Convergent 1. v., divergent o. v.: p. v. convergent, inserted just below vertex. 
Oc. divergent, inserted nearer front ocellus than hind. Ocellar area and front of frons 
with a few minute bristles. The head bristles are all proportionately rather stout for 
their length. Front view :—face shining black with a little sparse pale pollen; large 
second antennal joints separated at base by the beginning of the middle keel, which 
broadens into a distinct elongated knob reaching a little below the level of the third 
antennal joint. The forehead forms an arched recess in which the second joints of antenna 
are partly hidden; mouth-margin much convex. Side view (Plate 20, fig. 31) :—second 
antennal joint with two spines and a few bristles, rather ochreous; third small, also 
ochreous, arista with five top, two bottom and one end ray: inner row of five or six small 
and equal rays fairly evident. Vibrissa each side, with a row of fine bristles on margin of 
the broad, somewhat shining ochreous lower eye-margins. Hind jowls black and bristled. 
The post-orbital row strongest behind the verticals. Palpi dark ochreous and bristly as 
is the tongue. The shining clypeus is very evident in profile. 


| 
Se re NN 
Fig. 29. Drosophila rufuloventer, n. sp. x 40. 

Thorax. Entirely rather shining black, including the pleuree and the somewhat 
duller scutellum: the latter and the dorsum are covered with minute sparse pale pollen 
very regularly and beautifully spaced. The dorsum is also covered with regular bristles, 
pale in side illumination, which extend nearly to the back of the same. Two d. c., the 
discal bristles forming six-rowed acrostichals : the middle row of these ends in two small 
true presc. b. Two h., two n. p., presut., two sup. a., small post a. The scutellum is 
flattened on its posterior half: terminal bristles crossed about middle, equal side bristles 
subparallel. Wings, Fig. 29, with brownish veins. Halters darkened orange. Legs much 
darkened orange; front femora rather blackened, front tibize darker than rest ; inferior 
row of four distally placed front femoral bristles. 
Abdomen. Darkish russet brown, paler towards the tip. About two lines of discal 
bristles, and slightly longer marginal ones. 
Size, about 14 mm. ; wing, about 14 mm. 
Locality. Seychelles. Mahé: Caseade Estate, at or above 800 feet, IT. 1909. 
