CADDIS FLY LARVAE—FLINT 473 
cascade over rocks and boulders. The Illinois collection was made in 
a small dry streambed under a damp stone. 
The adults of this species have been collected from June through 
August, even in the same locality. The mature male pupa was found 
in Illinois in early October. 
Rhyacophila atrata Banks 
FIGuRE 4 
Rhyacophila atrata Banks, 1911, p. 351.—Ross, 1938b, p. 4 (male genitalia). 
This small species is known from Massachusetts, New Hampshire, 
New York, and North Carolina. 
A male metamorphotype from North Carolina assures the associa- 
tion of larvae and adults. The larvae may be recognized by their 
small size, immaculate head, and apicolateral spur on the anal proleg. 
Description: Length, 8 mm. Head, brownish yellow, immaculate 
(fig. 4,c); second segment of maxillary palpus about 1% times as long 
as first; left mandible with 2 apical teeth, right with 3 apical teeth 
all about the same length (fig. 4,5). Thorax, pronotum brownish 
yellow, becoming pale brown posteriorly; fore femora greatly broad- 
Ficure 4.—Rhyacophila atrata: a, anal proleg, lateral aspect; b, mandibles, dorsal; c, head 
and pronotum, dorsal. 
622304— 62 2 
