LAMB—DIPTERA: HETERONEURIDA, ORTALIDA, TRYPETIDA@, SEPSID@, ETC. 311 
4. Allometopon flavum, n. sp. (Fig. 3 and Plate 19, fig. 3). 
The species is entirely shining yellow except for slightly browner lines on the thorax, 
brownish tarsi, and the deep black third antennal joint and arista. The bristles are all 
distinctly yellow or brownish. 
The cheetotaxy agrees fairly with Kertész’s generic description, except that the ocellar 
bristles are not strikingly long. 
Head. Eyes bare. Top view :—frons orange, finely punctulate, darker and smoother 
on vertex round ocellar area: ocellar patch shining, eye-margin rather shining. Four 
f. o. b., all subparallel; nearly parallel i. v., divergent o. v., all these bristles arise from 
small papillee: p. v. small, divergent, inserted just behind middle of hind ocelli ; oc. small, 
divergent, inserted just on ocellar patch. The crossed bristles on front of frons are 
comparatively stout. 
In front view the antennz are seen to touch at base; the face is very narrow and 
short. In this view the stout subcylindrical yellow palpi are easily seen. Side view 
(Plate 19, fig. 3) :—the antennz much as Kertész’s description and figure l.c., p. 331. The 
orange 2nd joint is beautifully calyx-like, with bordering spines, one at the top being very 
long. The rounded rather flattened black third joint has a long blackish, distinctly 
pubescent arista. A stout vibrissa, followed by a row of marginal mouth bristles ; orange 
jowls, bristly behind, with one very long yellow bristle quite behind: six large post-orbit. 
bristles on top. 
Fig. 3. Allometopon flavum, n. sp. x 20. 
Thorax. Shining orange, with three narrow brown-orange stripes, evanescent 
behind: surface all covered with small bristles. The chzetotaxy agrees fairly with 
- Kertész’s description: two hind d. c. b., a much smaller one in front; two prescut. ; h. 
and n. p.are visible. The rounded orange scutellum has very fine pale pubescence : divergent 
terminal bristles, basal side bristles (scars only visible), 4 discal (on one side an extra 
one in the actual specimen). 
Wings, Fig. 3: yellowish with brown veins ; costa with strong double rowed bristles. 
Halters, orange. 
Legs. The front femora are strongly spined beneath from apex to base: the 
middle femora are also strongly spined in a row behind, the spines becoming progressively 
shorter from base to apex; the hind femora are unarmed ; the middle tibia has two very 
stout black end-spurs. 
Abdomen. Orange with rows of short discal, and long marginal bristles. 
