TABANIDA OF OHIO. 5 
of her abdomen to one arm of the V and depositing eggs along 
down until the apex is reached, then changing the tip of her ab- 
domen to the outer part of the other arm of the V and placing 
eggs along down to the apex on this side. 
This process is kept up, the female changing regularly to 
the outer part of the opposite arm of the V each time the apex 
is reached. Between nine o’clock and noon seems to be the favor- 
ite’ time of day for oviposition with the various species of both 
Chrysops and Tabanus, and I have seldom been able to observe 
females ovipositing at other hours of the day. 
The eggs when first laid are clear white but gradually get 
darker until they become permanently dark brown or black. 
Most of the eggs of Chrysops. are deep black, and are placed in. 
a single layer, but there are exceptions to this, for the egg of 
C. celer are never darker than brown, and are placed in at least 
three layers one upon the other. 
The color of eggs in Tabanus is variable between brown and 
black, and so far as I have observed, are always placed in convex 
masses composed of layers one upon the other. In sections of 
eggs just laid no great amount of development is observable, 
and we therefore conclude that eggs are laid soon after they are 
fertilized. Temperature has its influence on the incubation period, 
and for this reason the length of time required for the hatching 
of Tabanid’s eggs can not be said to be exactly so many hours. 
For instance, it took eggs of Chrysops callidus five or six days to 
hatch, and it required about a day longer in the case where eggs 
were kept in the shade the whole time, than in cases where the 
eggs were in the sun during the daytime. 
Eggs of Tabanus stygius hatched in about seven days in each 
of the two or three trials I gave them. In all species observed 
all the eggs of a single mass hatch very near the same time, and 
the whole mass of wriggling larve go tumbling down into the 
water together. Once in the water they separate and sink to the 
muddy bottom, where they conceal themselves so securely that 
they are not usually seen again until they appear as adults. Some- 
times there are a few eggs that are slow in hatching, and larve 
from these come out and drop to the water singly or in small 
groups. 
LARVA AND PUPA. 
The larve of the different species of this family are very 
much alike in appearance, except in size, consequently the full 
erown larve of the smal! species are hardly distinguishable from 
younger larve of the large species. They are tapering at each 
end, shining whitish in general color, and many of the larger 
specimens at least, are banded with dark brown or black. 
