474 NEW YORK STATE MUSEUM 
The larvae live at the bottom of streams of rapid water in the 
swiftest parts, under stones. They readily feed on soft bodied 
caddis worms, Sialis larvae, very young Chauliodes larvae, 
younger members of their own species; and doubtless have a 
wide range of food habits. I have succeeded in getting hungry 
larvae to eat bits of fresh beef by placing them in a tray of 
water in a photographic dark room. They do not feed well when 
exposed to bright light; and they seem to prefer live food. In 
the dark room they will sometimes eat large dipterous larvae. 
They spend the winter some distance below the bed of the 
stream buried in the sand and gravel. 
The larvae usually crawl when they care to move about in 
the water, but they can swim backward readily and sometimes 
are found to swim forward. 
Nothing very definite is known as to the number of molts or 
as to the length of the larval period. The same problems are 
here involved as those stated on a preceding page in speaking 
of Chauliodes larvae. I have kept larvae of Corydalis over 
winter in running water in dark cells made of flowerpots. Out 
_ Of 28 which were kept alive in the cells for nine months, only 
two were found to molt, and these do not warrant the drawing 
of any general conclusion. In September 1899 I took from one 
locality in Fall creek, Ithaca, over 100 larvae and measured 
their heads. The range of sizes was so gradual that it gave no 
clue to the probable number of years represented in the lot. 
Though the larvae naturally live in beds of streams till full 
grown, they are capable of living out of water in moist soil for 
an indefinite length of time. I thus kept them in a breeding 
cage in a greenhouse for over four months, at the end of which 
they were accidentally killed. The larval spiracles are doubt- 
less open and functional, at least when the insect is out of water, 
and may be used for breathing from air which collects under 
stones in running water. ; 
The mature larvae leave the water in May or June and pupate 
in cavities under flat stones near the stream. At times they 
crawl for many rods and even up high banks before selecting 
