110 Tre BuowFuiss or NortH AMERICA 
metallic reflections, dull orange and brown heads, orange-brown 
antennae and black legs. 
Male and female. Head (pl. 1, D) height usually less than 
width in proportion of 12:16 in female, 14:16 in male; length 
at antenna half head height, length at vibrissa somewhat greater; 
epistoma short, nearly as wide as clypeus, warped forward from 
elypeal plane and then not warped strongly downward; meta- 
cephalon rather flattened and but slightly produced posteriorly 
in profile; eye large, ovate in both sexes but upper and lower 
ares equal in female, the upper are much less than lower are 
in male; front obliterated in male at narrowest portion, the eyes 
nearly contiguous; frontal rows of bristles obsolete posterior to 
narrowest portion of front, moderately diverging anteriorly as 
they follow the margins of the frontale, and extending anteriorly 
to the base of the second antennal segment; inner vertical 
bristles decussate; outer vertical bristles absent in male; post- 
vertical bristles weak, proclinate; frontoorbital bristles absent in 
male, one strong reclinate and two weak proclinate in female; 
elypeus a little wider than one-fourth the length, deeply sunken, 
narrow; parafaciale narrowed above, bare; faciale rounded, 
steep, with two or three rows of short black setae which ascend 
nearly four-fifths the distance to the antennal base; vibrissa 
strong, above oral margin by 1.0; proboscis three-fourths of 
head height; palpus one-half as long as proboscis, clavate, the 
tip flattened; base of antenna slightly below eye middle when 
head is viewed in profile; antennal bases distinctly separated by 
a short and inconspicuous carina; third antennal segment reach- 
ing four-fifths the distance to the vibrissa; arista with plumosity, 
which is long above and short below, extending almost to apex; 
back of head in male concave above in profile, less obviously so 
in female, both sexes with one row of postocular cilia. 
Thorax with humeral bristles three, rarely four, strong; 
propleural bristles usually one, but sometimes two; preintraalar 
bristles two, the presutural bristle present; posthumeral bristle 
present; preacrostichal bristles absent or vestigial; predorso- 
central bristles two or three, weak, the posterior one placed 1.0 
before suture; presupraalar bristle one; sternopleural bristles 
usually three but sometimes only two; hypopleural bristles 
arranged in wide ‘‘V”’ along the posterior and dorsal margins of 
sclerite; prosternum large, wide; postalar declivity in center and 
anteriorly with hair tuft; preepaulet setose; tympanic pit thickly 
setose; tympanic ridge with a few short setulae; greater ampulla 
pilose or setose; postalar bristles two; postsupraalar bristles 
three; postacrostichal bristles one or two, only the prescutellar 
