NORTH AMERICAN CADDIS-FLY LARV. 
these segments there is a pair of slight prominences, each of which 
bears clusters of about five large and several smaller sete. 
The legs are long, and terminate in slender, curved tarsal 
claws; those of the first pair are shortest and stoutest, while those 
of the third pair are longest and most slender. The inner margin 
of each femur and trochanter is fringed with a dense single line 
of pale hairs. 
The Abdomen.—The segments are deeply constricted at the 
sutures, giving the abdomen a decidedly ringed appearance. The 
spacing-humps on the first segment are large; the dorsal hump is 
directed backward and bears a pointed nipple-like process at its tip; 
it is apparently incapable of motion; the lateral humps lack the 
nipple-like process and can be moved at the will of the larva. The 
lateral fringe is black, sparse in front, and growing increasingly 
denser toward the rear; the gills are long and finger-like, and are 
arranged singly; on each segment the hind gills of the medium 
line are stoutest and lie close to the body; their firm articulation - 
makes it apparently impossible for them to sway in currents, as 
do the other gills ; these postsegmental gills bear fine black hairs— 
continuations of the lateral fringe. On the dorsal surface of the 
ninth segment there is a raised chitinous plate which bears four 
prominent, and several small, sete on its hind margin. Above each 
proleg there is a line of several sete. 
DESCRIPTION OF THE Casks.—The cases are cylindrical tubes 
of thin, rectangular bits of leaves arranged spirally (Phryganea, 
fig. 41) or in a series of rings (Neuronia, fig. 18). The lining 
is a thin sheet of tough but pliable silk. 
KEY TO THE GENERA OF PHRYGANEIDA LARV. 
A. Frons with median stripe, or with no markings. Case a 
spirally wound cylinder.—Phryganea. 
A.A. Frons with dark markings, which are not in the form of 
a median stripe. Case a cylinder composed of rings of leaf 
sections placed end to end.—Neuronia. 
Key To THE GENERA OF PHRYGANEIDE Pup®. 
A. Mandibles lance-like, or sickle-like, several times as long as 
broad.—Phryganea. 
A.A. Mandibles rhomboidal, only slightly longer than broad.— 
Neuronia. 18 
