TRANSFORMATIONS OF BUFFALO GNATS. 9 
At Dallas, Tex., in March, 1913, JS. vittatum was found by the 
writer ovipositing in considerable numbers on the small stones in 
the limestone bed of a small stream which was almost devoid of 
submerged herbage. The eggs were laid generally below or at the 
surface of the water. In a few instances they were found an inch 
or so above the water, but this was owing to a decrease in the amount 
of water, which varies considerably in this and the majority of 
streams in Texas. This species has been found by the writer on one 
occasion at Havana, 111., ovipositing in large numbers on the bridge 
piles in the Illinois River. The eggs were deposited at or just below 
the level of the water, and as the river was falling at the time at the 
rate of an inch a day, the eggs underwent complete desiccation, and 
all were destroyed. The bridge piles were literally covered with the 
matrix and eggs, and many females, becoming entangled, died adher- 
ing to the viscous masses. This oviposition of this species in the 
main river seems to have been an abnormal occurrence, as the larvae 
have never been found in this situation. Another species, however, 
S. johannseni, according to the writer's observations, breeds: in 
enormous numbers in the main channel in the spring, around the 
submerged vegetation near the banks and wherever there is an 
obstruction. 
S. venustum, in the regions studied, belongs entirely to group 2. 
TKe eggs are laid on submerged grass blades and the like in small 
streams, in situations similar to those selected by S. vittatum. The 
eggs are more evenly arranged than those of that species, the matrix 
is not smeared so profusely, and the egg mass is generally oblong 
in shape and very compact. This species has many times been ob- 
served ovipositing, and specimens which subsequently laid a full 
quota of eggs in captivity were taken from the stream as they 
alighted. 
The oviposition in captivity of S. venustum was observed by the 
writer at Spartanburg, S. C, on September 16, 1913. A female 
8. venustum was noticed at 5.08 p. m. moving up and down a small 
stream within a space of about 4 feet, apparently seeking a suit- 
able place for oviposition. She would touch the water for an in- 
stant and then, apparently dissatisfied, fly up again. This peculiar 
interrupted flight was continued for a period of two minutes, after 
which she alighted on a grass blade which seemed to be satisfactory. 
Immediately a bottle was placed over her and she was at once taken 
to the laboratory. The stream from which the specimen was taken 
was situated 50 yards from the laboratory, and thus little time was 
lost in transit. The bottle in which the specimen was taken was 
partly wet inside. At 5.13 p. m., as soon as the bottle was placed on 
its side, she felt around for two minutes and then settled into posi- 
tion, rapidly thrust out the end of her abdomen, and deposited an 
10981°— Bull. 329—16 2 
