FAMILY CALLIPHORIDAE 
Although most of the diagnostic characters of calliphorid flies 
known to me are employed in the preceding key, a summary of 
characters which all such flies have in common is given here. 
MALE AND FEMALE CHARACTERS HELD IN COM- 
MON. Head usually, and often considerably wider than high, 
sometimes wider in female than in male; clypeus flush to deeply 
impressed, and most often half as wide as long but sometimes 
either wider or narrower; faciale usually slightly bowed; vibris- 
sae usually strong; proboscis rarely exceeding head height, 
usually one-half to two thirds as long; labella large; cheek 
grooves deep; palpi filiform, cylindric, or clavate, sometimes 
flattened, rarely short; antenna with first segment erect and 
usually flush with frons in profile, second segment two to four 
times as long as first, with a few strong setae dorsally, and with 
a laterodorsal longitudinal seam, third segment two to eight 
times as long as second, the lateral margins more or less parallel, 
the apex rather rounded; arista considerably longer than third 
antennal segment, penultimate segment of arista short and often 
somewhat bulbous, apical segment slightly thickened at base 
only, then gradually tapering toward apex, usually with long 
hairs which are sometimes less numerous and shorter below, 
rarely pectinate,* pubescent or bare; vertex narrower in male 
than in female; ocelli three; ocellar triangle often slightly raised; 
eenoorbital bristles absent; intrapostocular cilia present except 
in Rhiniinae and occasional specimens of Onesia and Melano- 
dexiini. 
Thorax with metanotum not divided except in Mesembrinel- 
linae in which the postscutellum is slightly raised; greater am- 
pulla raised, reniform; lesser ampulla swollen and differentiated 
from rim of postparapteron; hypopleuron with a well-defined 
row of bristles; intrahypopleural bristles undifferentiated; ptero- 
pleuron usually setose on posterior half or slightly more; 
pteropleural bristles in a well-defined tuft, none long; meso- 
pleuron bare on about anterior fifth; mesopleural bristles in a 
well-defined row; notopleuron setose; notopleural bristles usually 
two, rarely an adventitious third one between these; intrasterno- 
*Williston (1908) defined the term ‘‘pectinate’’ as follows: The arista 
is said to be pectinated if the hairs are fewer, stronger, and confined to one 
side. 
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