82 MISC. PUBLICATION 657, U. S. DEPT. OF AGRICULTURE 
and well-developed legs; the abdominal segments are each provided 
with a pair of lateral appendages, those on the ninth acting as graspers. 
The eggs are laid on overhanging trees, stones, or walls, in blotch- 
like white masses from 12 to 25 mm. in diameter and containing 2,000 
or more eggs. The larva of a small beetle is often found predaceous 
in these egg masses. The larvae, on hatching, fall into the water. 
Ficure 9.—The Dobsonfly (Corydalis cornutus): A, Larva, or hellgrammite; 
B, pupa; C, adult male; D, head of adult female. 
