HORSEFLIES OF THE SUBFAMILY TABANINAE a. 
Mesoscutum dark, with five pale-reddish stripes; prescutal lobe reddish; 
seutellum dark discally, reddish around margin; pleura and sternum gray, 
somewhat reddish on mesopleura, with white hair. Wing entirely hyaline, with 
dark veins; venation normal. Legs dark, with mostly whitish pile, the basal 
half of fore tibia and most of middle and hind tibiae orange brown; hind 
tibial fringe long, white except at darkened apex. 
Abdomen black, with a white median spot on first tergite, a pair of sub- 
lateral, oblique, whitish spots tinged with reddish on tergites 2-4, those on 
second prominent, a distinct median white triangle on tergite 3 reaching nearly 
half way to anterior margin, and a larger median triangle extending the length 
of tergite 4; all tergites with narrow white posterior borders, that on second 
slightly expanded medianly; venter dark gray, with hind margins of sternites 
whitish. 
Maie.—Eye somewhat fiattened above, the differentiation between the areas 
of large and small facets marked, the small facets extending around margin to 
vertex. Dorsal projection of first antennal segment very prominent. Colora- 
tion throughout essentially as in female. 
1 \ 3 
FicureE 16.—Antenna, front view of head, and palpus of (A) Tabanus dorsifer and 
(B) T. laticornis. 
Described from males from Arizona and Texas. 
Type.—Female, in the British Museum, 
Type locality.—Mexico. 
Mstribution—Arizona to Texas; Mexico. May 16 (Uvalde, 
Tex.) to October 9 (Santa Catalina Mountains, Ariz.). In the 
United States National Museum, eight females, six males. 
The types of both Tabanus dorsifer Walker and 7’. seavittatus 
Bigot were examined by Hine and in his manuscript notes are de- 
clared to be the same species as his 7. hyalinipennis. T. picturatus 
(Krober) from Venezuela is remarkably like this species, but the 
eye of the male in pictwratus is described as being composed of small 
facets only, and there are slight differences in the abdominal pattern. 
TABANUS LATICORNIS Hine 
(Fig. 16, B) 
Tabanus laticornis Hine, Ohio Nat. 5: 239-240, 1904. 
Rather small; blackish, with side of abdomen broadly orange; basal portion 
of third antennal segment orange, very short and stout, with no excision, apical 
portion black; frons rather broad. 
Female—Length 13-16 mm. Eye densely pilose, purple, with a slender, diag- 
onal, green band across middle at level of basal callus, a slender green band 
below, and a broad green spot near top. Frons gray tinged with yellow, about 
three and one-half times as high as width at base, widened above; basal callus 
shiny black, subquadrate, not touching eyes; median callus narrow, black, nar- 
rowly joined to basal callus; ocellar tubercle very small, not surrounded by 
denuded area; subcallus and upper margin of genae pale yellow; rest of genae 
and clypeus pale gray, with white hair. First two antennal segments yellowish 
or gray, with black hair, the first rather stout; third with basal portion orange, 
sometimes blackish apically, short and compact, about as wide as long, with 
no dorsal excision, the upper angle blunt; annulate portion black, about equal 
in length to basal portion. Second palpal segment pale creamy, with white and 
black hair, rather sicut at base, gradually tapering to a narrow apex. 
