Horn inoxious A rthropods 
oo. Legs unarmed; no crossvein between the 
branches of the radius (fig. 163c). New 
Mexico . Tersesthes Townsend 
mm. R-m crossvein present. 
n. Fore femora very much swollen, armed with 
spines below, fore tibia arcuate and applied 
closely to the inferior margin of the femur, 
o. R2+3 present, therefore cell R x and R 2 both 
present; wing usually fasciate. United 
States. Heteromyia Say. 
00. R2+3 not distinct from R4 + 5, hence cell 
R3 obliterated. South America. 
. Pachyleptus Arrib. (Walker) 
nn. Fore femur not distinctly swollen. 
o. R 2 + 3 present therefore cells Ri and R 3 
both present, or if not, then the branches 
of the radius more or less coalescent, 
obliterating the cells. 
p. At least the tip of the wing with erect 
setulae; tip of R4+5 scarcely attaining 
the middle of the wing, empodium rather 
indistinct, not reaching the middle of the 
claws, the claws not toothed, equal, with 
long basal bristle; legs without stout 
setae. Widely distributed. 
.Culicoides Latr. 
Haematomyidium and Oecacta are prob¬ 
able synonyms of this, 
pp. Wings bare, if rarely with hair, then the 
radius reaches beyond two-thirds the 
length of the wing, or the femur or 
fifth tarsal segment with stout black 
spines. 
q. Media unbranched. Europe . 
. Brachypogon Kieff 
qq. Media branched. 
r. Hind femur much swollen and spined. 
America and Europe. Serromyia Meg. 
rr. Hind femur not distinctly swollen, 
s. Cell Rj not longer than high; fork 
of the media distad of the cross¬ 
vein; wing with microscopic setu¬ 
lae . Stilobezzia Kieff 
ss. Cell R r elongate. 
t. Femora unarmed. Widely dis¬ 
tributed. (= Sphaeromias Kieff. 
1913 not Curtis?) . 
.Johannseniella Will. 
