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66 INSECTS AFFECTING DOMESTIC ANIMALS. 
The imago, known as the ‘‘greenhead,” is very generally common, and is quite a 
pest in some bottom land prairies. A few examples were noted along shore at Sta- 
tion D, August 20. The examples in our collection were taken on twenty-two occa- 
sions, all between July 15 and August 13, except three dates, July 8 and August 18 
and 31, which would make it probable that it is smgle brooded. The localities are 
Carroll Lake, Cook and Ford counties at the north, and Fulton, McLean, and 
Champaign counties in central Illinois. The specimens were from a variety of situ- 
ations, usually in low herbage, often taken visiting flowers. 
Larva: Length, 20 mm.; diameter, 2.7 mm.; prothorax with lateral shining areas 
about as long as the dorsal, coarsely striate, a smooth spot near center of disk; dor- 
sal and ventral areas of thorax smooth, a few strizx cn those of metathorax, especially 
posteriorly; remaining areas moderately striate, lateral areas of abdomen a little 
more finely striate than the others; all more or less shining. 
Dark annuli pale, narrow, longitudinal stripes scarcely present; false feet with 
dull pubescent crests, their sides rather finely striate; a narrow dark annulus at 
base of respiratory tubes, another round base of last segment, inclosing anal promi- 
nence and giving off a pair of lateral stripes, the lower one longer; no projecting 
spines seen. 
Pupa (from defective cast skin of male): Length, 20 mm.; diameter, 3 mm.; light 
fuscous brown, shining; abdomen smoothly wrinkled; slightly opaque; prothoracic 
spiracular tubercles slightly but nearly equally elevated, free margin rounded at 
tip, rima not vertical, evenly arcuate, slightly hooked in front. 
Abdominal spiracular tubercles small, subtriangular, narrower behind, obliquely 
subconical, much shorter than basal diameter, bearing a very small subcircular 
ting; fringes formed of unequal pale spines, the longer ones sparse on seventh seg- 
ment above; outer terminal teeth twice as large as lower pair, directed laterally 
and slightly backward; upper pair smallest, directed upward; ventral fringe of last 
segment not noticeably webbed; lateral tufts rather high, not near ends of ventral 
fringe. 
My material of this species is not in best condition for accurate comparisons. 
Tabanus annulatus Say. 
This species was described by Say in 1822 (Jour. Acad. Phil., Vol. II, 
p. 31; Comp. Writ., Vol. II, p. 53), and its territory stated as Missouri. 
It does not seem to have received special notice since. 
It is probably not abundant enough to cause serious annoyance to 
stock or is commonly confused with some more common species and 
has consequently received little attention. 
It is smaller than Tabanus lineola, the length of the body being a 
little mure than two-fifths of an inch. 
It is of a leaden-gray color tinged with reddish; the abdomen black- 
ish brown with gray margins to the segments, the wings without spots 
and slightly dusky. (From Say’s description. ) 
Tabanus stygius Say. 
This species is almost as large as Tabanus atratus Fab., nine-tenths 
of an inch in length and occurs in the Mississippi Valley. Say’s 
description in 1822 (Jour. Acad. Nat. Sci. Phil., p. 33) locates it in 
Arkansas. 
It is violet black and with the thorax pale chestnut. The front of 
the head is yellowish, the thorax with five gray lines, the wings rusty 
with three brown spots. (From description of Say.) 
