NORTH AMERICAN CADDIS-FLY LARVZ. 
the eye, the upper margin of this mark is bordered by numerous 
small round spots and near its cephalic end a narrow line extends 
downward, connecting it with the black mark of the venter; each 
side of the venter is marked by a broad black patch which extends 
from the base of the mandibles to the caudal margin of the head; 
the mandibles are jet black, except for a brown mark on the outer 
margin. 
The Thorax —The markings of the dorsum are shown in 
figure 2; on each side of the third segment a sharply defined black 
mark extends obliquely upward to the caudal margin of the seg- 
ment; on the venter there is a black, somewhat triangular mark 
reaching from the caudal margin of the segment to the base of 
the “horn;” the “horn” is light in color and apparently weakly 
chitinized. The second thoracic segment has a group of about 
eight sete in a light-colored area on each side of the dorsum; the 
sides, except the legs, are without markings; the venter is without 
markings; the third segment has a group of about eight sete on 
each side of the dorsum, its sides and venter are without markings. 
The legs are straw-color marked with black. 
The Abdomen.—In life it is dark-green with a distinct reddish 
tinge, especially on the dorsal side; the gills are pale reddish; the 
arrangement of gills is diagrammatically shown in figure 6. 
DESCRIPTION OF THE Pupa.—Description made from a cast 
skin. The mouth parts are weakly chitinized; the labrum is rec- 
tangular with rounded corners, about 1.5 times as long as wide; 
the mandibles are about half the length of the labrum and are 
almost as broad as long, a projection on the outer side bears two 
prominent sete on its tip; the lateral fringe commences on the 
cephalic margin of the fifth abdominal segment and loops under 
the caudal margin of the eighth segment; a pair of sucker-like 
discs occurs on the dorsal surface of the caudal margin of the last 
abdominal segment; each disc has a single seta on its outer mar- 
gin and a group of three large sete beneath its cephalic margin; 
the first abdominal segment has a striate appearance above, as in 
figure 8. The arrangement of teeth on the dorsal plates is serially 
illustrated in figure 8. 
NEURONIA POSTICA. 
Hasitat.—This species is found in cool, slowly moving 
streams, fed by springs or in drainage from upland bogs. Like 
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