43. 
44 
. (41) 
45, 
46. 
47 
. (40) 
48. 
49, 
50. 
51. 
(48) 
(47) 
06. (53) 
58. (39) 
59. 
60 
. (58) 
61. 
HORSEFLIES OF THE SUBFAMILY TABANINAE 
Key to Nearctic Females of Tabanus—Continued 
Wing hyaline, the costal cell dark brown; (abdomen usually 
banded! wath eraly 220823 26 se americanus Forster, p. 83. 
Wing uniformly dilute brown, the costal cell yellow 
giganteus Degeer, p. 84. 
Cell Rs not narrowed apically_______ turbidus Wiedemann, p. 112. 
Celli; narrowed apically... = Si ee ee 
Legs nearly uniformly orange brown_------_-~_~-______________ 
Hemoray atleast, blacks S221 — Pans a gladiator Stone, p. 85. 
Base of third antennal segment with a prominent, forward-pro- 
jJectineg process... is a _imitans Walker, p. 86. 
Dorsal angle of third antennal segment not projecting forward 
imitans var. excessus, new variety, p. 87. 
Fureation without a distinct dark cloud, although whole wing 
may be infuscated or petiole of cell Rs may be margined with 
Fureation with a distinct dark cloud 
Basalgcallus: transversen 2). cena ead Oe Pe i) Sh 
Basal callus square or higher than wide_____-----_____________- 
Mesoscutum with bright-orange hair laterally 
atratus var. fulvopilosus Johnson, p. 89. 
Mesoscutumeentirely Gark haired. 20-2 eile se 
Wing uniformly dark brown to black____atratus Fabricius, p. 87. 
Wing brown, with a distinct yellowish tinge along hind margin 
atratus var. nantuckensis Hine, p. 89. 
Frons more than six times as high as basal width, widened 
above; veins of basal portion of wing margined with brown 
morbosus, new species, p. 89. 
Frons less than four and one-half times as high as basal width, 
with parallel sides; wing either nearly hyaline or deeply 
InN Se Aue (lace ee wea teancncaree, EL FY AOA a SS) AE 
Wingmnearly byaline. 20 92 e acgrotus Osten Sacken, p. 90. 
Wing deeply infuscated__-______ wiedenianni Osten Sacken, p. 91. 
Mesonorme dark brown: to: black.~-2.--224-2 =. 3 
MeSonoO mimi ale mes ts. Sk ete AONE 22 UR a oh he WER Be 
Frons narrow, distinctly widened above; antenna mostly orange 
prozimus Walker, p. 91. 
Frons moderate in width, with nearly parallel sides; antenna 
TTLO SOMA eA Cg es Seg EN hes Thee I SS ee 
Wing nearly hyaline distad of basal cross veins 
nigrescens Palisot, p. 92. 
Wing nearly black__--__-_ nigrescens var. atripennis Stone, p. 98. 
Fore tibia bicolored ; (western) ____punctifer Osten Sacken, p. 93. 
Moremeibiasunmormily— darko 2220 Lu ti set ees ee 
Frons moderate in width, orange brown______-~- styqins Say, p. 94. 
Hronsivery broad, graye. 222) 222-8 subniger Coquillett, p. 95. 
Abdomen orange brown, with a median dark area which expands 
posteriorly; (wing fumous or spotted with brown) —---___~ 
Abdomen with a single median row of pale spots or with a 
stripe, with or without lateral pale spots_____________-_-__- 
Median dark area of abdomen a row of dark, subquadrate spots ; 
femora iblack22ee 225 2 kk abdominalis Fabricius, p. 116. 
Median dark area continuous; femora orange brown 
fumipennis Wiedemann, p. 96. 
Abdomen with a single median row of pale spots not forming a 
parallel-sided stripe; these sometimes arise from apical 
bands which widen toward lateral margins but do not form 
distinct: sublateral’ ‘spots: or’ triangles__-2-2—-—-- =) 
Abdomen with a parallel-sided stripe, with or without sublateral 
SWOLSUORESERIP CS ne ats 2th AM hl). Ea oe Sa PO ee 
No spot on tergite 2; fore tibia distinctly bicolored; venter of 
abdomen with a distinct, median, brown stripe; furcation and 
cross veins faintly margined with brown 
trimaculatus Palisot, p. 96. 
A pale spot on tergite 2, sometimes very faint; and differing in, 
at least, one other character mentioned___~-_--------~---- 
41 
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46 
52 
54 
56 
55 
oT 
59 
60 
61 
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