132 
Psyche 
[Sept. 
land to the Island over a gravel road that rises only 2-4 
feet above the marsh. Usually I drive along this cause- 
way to the mid-section where a small ditch, running 
parallel to the road on the north, overflows to form a 
broken chain of small shallow pools. Where these begin 
I shift into low gear and drive on slowly while watching 
for Tabanids. The larger ones are readily seen and egg 
masses can frequently be spotted in this manner. It is 
convenient to turn in a driveway at the edge of the Island 
and then drive back to park beside the ditch wherever 
anything of interest has been noted. Ordinarily, oviposit- 
ing females are not easily disturbed and they may be 
casually approached without any special precautions. 
My experience with the first female is of some interest 
in this respect. She was busy ovipositing on a blade of 
Spartina glabra Muhl. var. alternijlora (Loisel.) Merr. 
which grew thinly in the shallow water of the pond margin. 
They show a strong preference for scattered culms rather 
than dense stands and eggs were found only on this plant. 
It was about 4 p.m. when she was first observed as I drove 
towards the Island. (All time E.D.S.T.) There I turned 
and went back to park as indicated above. Then I crossed 
the ditch and skirted the pond to get a closer look at her. 
She seemed quite indifferent as I carefully moved to 
within a foot of her and even touched the tip of the blade 
she was laboring on. For several minutes I watched her 
lay her eggs in the manner so well described by Hine 
(1903, 1906) for Chrysops callidus 0. S. and C. moerens 
Walker. Then I decided to return to the car for a con- 
tainer in which to take her alive. She was still at work 
when I got back, but just as I was reaching out to lower 
the jar over her she flew away. Her egg mass was prob- 
ably nearly complete since she had been ovipositing for 
at least an hour by that time. It measured 15 mm. long 
by 5 mm. wide at the base. The eggs were glistening 
white then but by 6 p.m. had become dull and somewhat 
greyish. By 9 : 30 the mass was mottled greyish brown 
and subsequently darkened but slightly. The upper ends 
of the eggs are a bit darker, which gives the appearance of 
stripes on close inspection since they are so uniformly 
