1953] 
Fairchild — M exican Tabanidae 
47 
borders, broad median longitudinal yellowish bands which 
reach both margins but are narrower anteriorly and small 
round isolated yellowish dorsolateral spots, one on each 
side. Seventh tergite brown with yellow posterior border. 
The brown areas and the dorsolateral spots are clothed with 
black hairs, the remaining yellow areas with yellowish 
hairs. Beneath the abdomen is thinly grey pollinose, wholly 
pale haired. 
Male. 8-9 mm., of wing 7-8 mm. Head enlarged, eyes 
bare, holoptic, the area of large facets somewhat over 1/2 
total eye area, the two types of facets well differentiated 
and demarkated. Large facets brown, small facets purple 
with two narrow green bands and a small segment of a 
third band at extreme outer angle. Tubercle at vertex 
deeply sunk between eyes, hardly discernible. Frontal tri- 
angle yellowish grey pollinose. Antennae more slender 
than in female, yellow, the annulate portion black. Palpi 
inflated, porrect, cylindrical but ending in a sharp point, 
clothed with long black and white hairs. Wings, legs, thorax 
and abdomen as in female, except that the abdominal color 
pattern is less sharply marked, the pollinosity sparser and 
all hairs longer. The abdomen is also very much more 
slender, the last few segments narrowed almost to a point. 
Holotype, female. Hacienda Sta. Maria, on Rio Sta. 
Maria, 35 km. north of Cintalapa, Chiapas, Mexico, 15 
April 1951. 
Allotype male, same locality, 11 April 1951. 
Paratypes 28 females, 7 males, same locality, 11, 15 and 
18 April 1951, attempting to bite the collectors or in a 
Shannon trap. All Fairchild and Hartmann colls. 
This little species appears to most nearly resemble St. 
crihellum 0. S., sharing with it the presence of a bare patch 
at vertex, but no true tubercle and having a similar frons 
and callus. In rubbed specimens the trident-shaped median 
callus shown by Stone (1938) for cribellum is quite evident. 
The male, however, has but a vestige of a vertical tubercle, 
deeply sunk between the eyes and difficult to detect and 
the facets are very well differentiated, somewhat in con- 
trast to the male of cribellum described by Philip (1941, p. 
11). The abdominal pattern and spotted wings will easily 
