AQUATIC INSECTS IN NEW YORK STATE (445 
The masses are often quadrangular but are variable in out- 
line, and are not coated with any protecting material. Several 
masses are very commonly found near each other; in one case 
about 150 masses were found within an area 6 by 12 inches; and 
the remains of the masses of former years are also found near 
the fresh eggs if the place be a suitable one. The eggs are all 
placed in a slanting position, i. e. not perpendicular to the sur- 
face of attachment; and are all parallel to each other, in one 
layer, with the micropylar projection outward. Exact counts 
and estimates show that the number of eggs in a mass is usually 
from 200 to 500 [pl. 51]. 
Life history of Sialis infumata 
It is an interesting sight to see a female depositing her eggs. 
This I have witnessed on several occasions. 
She deposits an entire row of 10 to 20 eggs 
and then begins another row; as the rows 
accumulate, she moves backward over the 
mass to reach the place for the succeeding 
rows; thus her body and wings cover the 
- ege mass till it is completed. The eggs are 
always deposited over ‘water or in a place 
where the young larvae will naturally fall 
into water. I found them on the under 
sides of boat landings, on the under and 
vertical sides of bridges, on stones project- 
ing above the water of creeks and lakes. 
Stagnant pools are not attractive to mem- 
bers of this genus. The adults do not seem A~E 
to select the twigs or leaves of trees and AS 
shrubs when such objects as those above S 
mentioned are accessible. When a high 
bridge is selected by the adults, on which = yy, 9, rarva of Sialis 
to deposit their eggs, they know where the eee 
limits of the running water are, and deposit the eggs within 
those limits. 
After seeing females deposit their eggs and after noting the 
dates when other new eggs were deposited, say on a given rock, 
