CALAMOCERATIDE. 
margin of the seventh abdominal segment, ends at the beginning 
of a fleshy raised line, figure 155, which crosses the suture between 
the seventh and eighth segments and, inclining upward, extends 
to the caudal margin of the eighth segment. Each side of this 
fleshy line is armed with curved, bifurcate spines directed back- 
ward. The anal hooks and the arrangement of sete on the last 
abdominal segments are shown in figure 155. 
DESCRIPTION OF THE Pupa.—Length, 13 mm.; mandible, fig- 
ure 150. ‘Tarsi flattened and fringed on each side by a row of 
black swimming hairs. Lateral fringe black. A narrow black 
line parallels the lateral fringe beneath, extending to the caudal 
margin of the eighth segment, where the two converge. A nar- 
row black line above the lateral line contains the spiracles. Ab- 
dominal segments 2 to 9 have tufts of hair near their caudal 
margins above. On the caudal margin of the first abdominal seg- 
ment there is a pair of lobes, figure 161, covered with sharp spines. 
Above these lobes are sparse backward-pointing teeth. The chiti- 
nous plates of the abdomen are shown in figure 161. The pos- 
terior end of the pupa is represented in figure 157. 
Tuer Case.—The cases made by this species differ greatly from 
those of other described American Trichopterous larve. Instead 
of the usual dwellings of stones or twigs, or tubes of silk, these 
utilize fallen twigs of wood from the stream-bottom. The twigs 
are hollowed from end to end, and lined with silk, forming porta- 
ble cases, which are a natural part of their surroundings. These 
larve abound among the litter of branches and twigs from the 
surrounding forest. In spite of their abundance they are most 
inconspicuous among the débris. They crawl with a jerky motion, 
as if swayed by the passing current, or rest, as if lodged, on a sub- 
merged branch, and when disturbed, let go, drifting down stream 
with the current. 
The twigs used in cases vary greatly in length and diameter, 
apparently being selected at random from the litter on the bot- 
tom of the forest stream. Sometimes pieces of heavy bark or 
fragments of broken wood are used. A cylindrical hole always 
penetrates the wood from end to end. In some twigs the chamber 
forks near the anterior end, one outlet curving downward and 
opening to the exterior at one side, while the other perforates the 
end of the stick. The side outlet, when present, forms the anterior 
gi 
