FLIES OF THE TRIBE LESKIINI—JAMES 99 
Front slightly convex; vertex a little more than one-third head 
width, not significantly different in the two sexes; width of frontalia 
slightly less than that of a parafrontal; epistoma in clypeal plane; 
parafacial twice as wide at base of antennae as at narrowest point; 
cheek one-fourth to one-third eye height. Haustellum at least almost 
head height, very slightly bowed, cylindrical on basal half, then gently 
constricted and gradually enlarging again toward apex, on apical half 
pigmented and with setulae arising from pigmented pores; labella 
small; palpus bowed, approximately as long as third antennal segment, 
spatulate, longer and much more strongly swollen in female than in 
male. Third antennal segment 2.5 to 3 times as long as second; hairs 
of arista one to two times as long as its basal diameter. Lateral 
postscutellar plates bare. Tarsi somewhat longer than tibiae; claws 
in both sexes short. Cell R; narrowly open to very short-petiolate; 
vein R, setulose to apex, setulae on stigmatic section shorter and more 
closely set than elsewhere. 
Chaetotawy.—Postocellars not decussate; outer verticals indistin- 
guishable from postocular setulae; ocellars moderately strong; two 
proclinate and two reclinate frontoorbitals in both sexes, the hind 
bristle of each series usually distinctly shorter than the fore one; 
four to six frontals, the anterior two small, the first distinctly below, 
the second slightly below but almost level with bases of antennae, 
the first rarely duplicated. Two presutuaral acrosticals, well- 
developed and distant from suture; three presutural dorsocentrals; 
three humerals; two postalars; two lateroscutellars, the hind pair 
not decussate; 1 moderately small pteropleural; three to six hypo- 
pleurals. Prosternum bare. Median marginals absent from first 
abdominal segment and rarely present on second, 
Coloration and vestiture-—Head yellow in ground color except 
upper third to half of lateral occipital plates, which is blackish. 
Frontalia with scattered pollen showing only from certain angles; 
head otherwise with dense whitish to yellowish pollen. Parafrontals 
with a few scattered fine black hairs; a few setulae of varying size 
around each vibrissa; occiput with black setulae on upper fourth, with 
softer yellow hairs below. Antenna yellow; third segment with an 
orange cast basally but infuscated on a large part of its area, the 
infuscation darker and more extensive from an outer than from an 
inner aspect. Proboscis yellow, apical third to half of haustellum 
and the labella brownish; erect hairs of haustellum rather dense, 
short, one-third to one-half as long as diameter of haustellum; labella 
with a few scattered black and yellow hairs. Palpi yellow, with scat- 
tered short, spinelike black setulae above and a few fine black hairs 
and one or more preapical setulae below. 
Thorax dull black in background, except humeri, propleura, and 
certain other pleural areas, which are yellow; each inner mesonotal 
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