Vorhies—Studies on the Trichoptera of Wisconsin. 683 
line. Lateral humps thickly beset with small spines, set in 
pairs. Dragging hooks composed of a series of small hooks dis¬ 
posed in a fan shape, the largest hook on the outer side. The 
piece bearing this series of hooks is concave and well adapted 
to fit the curved interior of the case. A sharp spur on the 
supporting plate of the first leg extends forward, ending in a 
spine. 
Pupa. —Length, 6-7 mm. Antennae extending to the 7th 
segment. Body yellow to greenish. Dorsal spines, III, 3. 3. 
3+3-4. 3, VI. Ao gills and no lateral line. Posterior end of 
body terminated by a pair of stout, club-like projections, each 
bearing 11-12 long, black, terminal hairs. Mandibles long, 
slender, finely serrate within, crossed at the tips, which are 
slightly turned outward; much longer than the labrum which 
is very small, a little broader than long, with two anterior 
groups of three hairs each, and two posterior pairs of hairs. 
Eggs .—Hundreds of clusters of the eggs of this species might 
easily be collected from the posts of piers which stand in the 
waters of the lakes in the latter part of June and early July. 
They are contained in clear or slightly yellowish hemispherical 
masses of soft jelly, 3-5 mm. in diameter, which are deposited 
several inches below the surface of the water. 
Case .—The larva of this species builds the famous case char¬ 
acteristic of the genus,—a spiral like a common snail shell, and 
several times described as such. As an example of such a mis¬ 
take may be given the description of arenifera, by Lea (1834). 
He says it “has the remarkable property of strengthening its 
whirls by agglutinations of particles of sand, by which it is en¬ 
tirely covered.” 
The case is very strongly built of evenly sized sand grains 
accurately placed. Diameter of tube at mouth, 2 mm. Height 
of coil, 3 mm. Whole width of coil, measured across the mouth, 
5 mm., and at a right angle to this 4 mm. Usually about two 
whorls to the posterior opening. Larvae killed in the case are 
found to extend around more than an entire whorl, the average 
perhaps 1 1-4. 
The pupal case is identical with that of the larva, and is 
found fastened upon stones, particularly rough or irregular 
