ver 
7 
SY Pe ey, 
—— a 
DIPTERA. 61 
of some building. The eggs are doubtless deposited in the vicinity of 
water, in moist places, but the exact details of oviposition are unknown. 
The larva (fig. 22, a) is a large, 
twelve-jointed, cylindrical affair, 
tapering at each end, of a trans- 
parent, highly polished, glassy, 
yellowish, or greenish appear- 
ance, shaded with bluish green 
and furnished above and below, 
as 1n the figure, with large, round- 
ish, sponge-like tubercles which 
are retracted or exserted at the 
will of the insect. Though the 
external integument is so trans- 
parent that the internal structure 
is readily visible, yet this integu- 
ment is firm and the larva most 
vigorous and active, burrowing 
with great strength either back- 
; Fic. 22._Tabanus atratus: a, larva; 6, pupa; c, adult 
ward or forward in the earth and (after Riley). 
between one’s fingers when it is 
being held. Placed in water it will swim vigorously by suddenly curling round and 
lashing out its tail, but it is apparently not as much at home in this element as in 
the moist earth, for it is restless and remains near the surface with the tip of its 
tail elevated in the air. When the water is foul, it moves about actively near the 
surface, but when it is fresh it remains more quiet at the bottom. 
The specimen which I succeeded in breeding was sent to me by 
Mr. Adolph Engelmann, of Shiloh, St. Clair County, Ill. It was 
found by Mr. William Cooper, of the same county, about 10 feet 
from a small but permanent body of water. Mr. Cooper at first 
took it to be a leech, and when he attempted to capture it it 
immediately commenced burrowing in the ground. 
The larva reared by DeGeer was terrestrial. This 
larva is Semiaquatic, for it is quite at home either in 
moist earth or water. My specimen was kept for over 
two weeks in a large earthen jar of moist earth well 
supplied with earthworms. 
It manifested no desire to come to the surface, but 
burrowed in every direction below. I found several 
pale, dead worms in this jar, though I can not say pos- 
itively whether they had been killed and sucked by 
this larva. Mr. Walsh, in speaking of its haunts and 
its food, says: 
I have, on many different occasions, found this larva among 
floating rejectamenta. On one occasion [ found six or seven 
specimens in the interior of a floating log, so soft and rotten that 
ae it could be cut like cheese. Once t discovered a single specimen 
atratus: larva Underaflat, submerged stone, in alittle running brook. Finally, 
(from Hart). I once met with one alive, under a log, on a piece of dry land 
which had been submerged two or three weeks before, whence it 
appears that it can exist a long time out of water. I had on several previous 
occasions failed to breed this larva to maturity, and the only imago I have was 
