204 
4. 
THE BLOWFLIES OF NortH AMERICA 
¢ 
Length of head at antenna and at vibrissa more than half 
head height; second abdominal segment with long and 
erect median marginal bristles....................6- 
Length of head at antenna and at vibrissa less than half 
head height; second abdominal segment without median 
marginal. bristles. s.<<. $2.95 5. 4s. Eh apf - 5) eee ee 
. Two postacrostichal bristles; front at narrowest 0.14 of 
head width in male, 0.35 in female. (Nearctic)...... 
pu CAR eee re ae Bufolucilia elongata (Shannon), p. 216 
Three postacrostichal bristles; front at narrowest 0.08 of 
head width in male, 0.31 in female, (Holarctic)...... 
tr aan See Aa Ie Bufolucila silvarum (Meigen), p. 219 
. Three’ postacrostichal’ bristles :....0).s 1... ..ctenee ee 
Two: postacrostichal bristles. : 3.0. 0)).... 222.10). dene 
. Male with but one ocellar bristle and front rarely ex- 
ceeding 0.12 of head width; bucea in both sexes greater 
than 0.25 eye height, metasternum setose, and body 
color ‘light or dark blue-green... 12)... eee 
Male with two proclinate ocellar bristles, the posterior 
bristle weak; front at narrowest 0.18 of head width 
in male; bucea in both sexes about 0.25 eye height, 
metasternum bare, and body color aeneous or yellowish 
green. (Nearctic) Phaencia pallescens (Shannon), p. 247 
. Male with front at narrowest 0.11 of head width, parafaei- 
ale opposite lunule 0.66 of width between vibrissae, 
bueca 0.34 of eye height; female with frontal margins 
nearly parallel, front 0.34 of head width; bueeca 0.38 
of eye height. (Holarctic), . 1.04. 0. +us% «se ee 
FE i es | Phaenicia sericata (Meigen), p. 259 
Male with front at narrowest 0.05 of head width, parafaci- 
ale opposite lunule 0.33 of distance between vibrissae, 
and bucea 0.28 of eye height; female with front 0.32 
of head width at vertex, the frontal margins narrowing 
anteriorly so that front is but 0.31 of head width 
slightly above lunule, and the bucea but. 0.27 of eye 
height. (Nearctic) Phaenicia thatuna (Shannon), p. 269 
. One row of postocular cilia; second abdominal segment 
with a weak row of marginal bristles................ 
Two or more rows of black postocular cilia; second ab- 
dominal segment without a row of marginal bristles. 
(Nearctic) Phaenicia mexicana (Macquart), p. 2438 
