NORTH AMERICAN CADDIS-FLY LARVE. 
head; a dark-brown mark begins slightly behind each mandible 
and follows the inner margin of the frons until nearly reaching 
its caudal angle, where it makes a U-like curve, leaving a small 
area of the caudal part of the frons unmarked. 
The Thorax.—The sternum of the prothorax is straw-yellow, 
the dorsum marked with a somewhat variable pattern of smoky 
brown, as shown in figure 19; the episternum is smoky brown in 
color, narrowly bordered with deep black along its hind and lower 
margins; on the under side the prothorax is straw-yellow, except 
the chitinous triangle, which is dark-brown. The mesothorax has a 
variable pattern on its dorsal surface; it also has two dark-colored 
chitinous plates near the mid-dorsal line. The metathorax has a 
variable pattern on its dorsal surface. 
The Abdomen.—The soft abdominal parts of the material at 
hand have been injured by drying. 
GENUS PHRYGANEA. 
Hasrrat.—In this region Phryganea larve have been found 
only in the ponds and pools of the Renwick marshes and in Mich- 
igan Pond. Occurrence of adults at Sheldrake Point, where there 
are similar ponds, and on the campus, near Beebe Lake, makes it 
seem probable that the genus is not uncommon where suitable 
ponds of thick submerged vegetation exists. 
LarvaL Hapritrs.—Phryganea larvee dwell, for the most part, 
among submerged plants above the water’s bottom. They are 
among the few Trichoptera larve that can readily be taken with 
a water net. In moving from place to place, however, when the 
branches of the supporting plants are not intermixed, they must 
become bottom-crawlers. Unlike Triznodes, a genus of Lepto- 
ceridee, with which their cases and habits have some things in 
common, they are not provided with swimming hairs, and are in- 
capable of progress by swimming. Phryganea larve differ from 
the larvee of Neuronia in their persistent occupation of their cases. 
They never abandon their cases to wander naked through the 
water. Correlated with this habit one finds their cases more 
tapered than those of Neuronia, indicating that they have been 
retained through a period of growth. 
In preparing to pupate, the larve of Phryganea leave their 
abode among the living plants and travel to some submerged log 
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