NORTH AMERICAN CADDIS-FLY LARVZE. 
holes which they had evidently made for themselves, though some- 
times they were in cracks or between the bark and the wood. The 
front ends of the cases were fastened tightly, sometimes so tightly 
that pressure broke them before pulling them loose from their 
support. 
Foop oF THE LARva:.—Stomachs examined contained almost 
entirely green leaves of aquatic plants. Only a few contained dead 
vegetation, but the choice undoubtedly was due to the environment 
of feeding, rather than to any choice of the larve. 
Periop oF EMERGING.—Specimens emerged June Io to 20. 
Emergence was not observed, but the similarity of Phryganea 
pupz to those of Neuronia in habitat, habits, and structure in- 
dicates that emergence is accomplished as in that genus. 
DESCRIPTION OF THE Larva.—Length, 25—30 mm.; breadth, 
3.5 mm. In life the color of the chitinous parts is pale straw- 
yellow with dark-brown markings. 
Head.—The color pattern of the upper surface of the head is 
shown in figure 38; its ground color is straw-yellow, lighter around 
the eyes; a dark-brown mark extends back from the base of each 
mandible, touching the margin of the frons, and passing on to the 
hind margin of the head; on the sides of the head an oblique dark 
mark begins behind each eye and extends back to the hind margin 
of the segment, paralleling the dorsal dark mark. The eyes are 
jet black. The frons (figure 43) is straw-yellow without mark- 
ings, but is slightly darker than the ground color of the head. The 
mandibles are stout; the left mandible has three teeth above and 
three below, while the right mandible has but two teeth above and 
two below. 
The Thorax.—The prothorax is straw-yellow with two oblique 
dark-brown marks, forming continuations of the lateral marks of 
the head, on its upper surface. The posterior sclerites of the pro- 
pleura are dark-brown, margined with black on their caudal and 
lower margins. 
The meso- and meta-thorax are brownish green in life, marked 
somewhat as shown in figure 38; the markings of these segments 
vary somewhat in different specimens. 
The legs are straw color with dark-brown markings on each 
coxa and a mark of lighter brown along the back of the front 
femur. The legs are more slender than those of P. interrupta, and 
36 
