Vorhies—Studies on the Trichoptera of Wisconsin. 701 
■segment, the dorsal portion of it bearing two small chitinous 
processes just before the end. Labrum very small; mandibles 
long and slender, with broad base and incurved distal portion 
bearing small teeth within and at the base of the curve. 
Case. —Length, 10-11.5 mm. Width, anterior, 1 mm.; pos¬ 
terior, less than % mm. Cylindrical, slightly curved, formed 
‘entirely of clear secretion. 
At time of pupation a bell-like rim is formed at the anterior 
end, and the case is attached to Ceratophyllum by a band of 
silk. The posterior closing membrane, placed some distance 
from the end, is funnel-shaped, pointing backward, and the an¬ 
terior membrane is a disk, slightly concave interiorly, with a 
eentral perforation. The cases fit the larvae and pupae very 
closely. 
Habits and Occurrence .—In the autumn, if plant material be 
brought in from certain localities and placed in large aquaria, 
immense numbers of the young larvae of this species will in a 
few hours collect on the lighted side. They often form a drift 
in the angle along the bottom, from which some are continually 
swimming up and dropping back. The case being transparent, 
the bright green body of the larva or pupa shows thru it and 
is thus well protected in its natural habitat. Especially is this 
true at pupation time, about July 1, when the pupal cases are 
fastened among the spine-like leaves of Ceratophyllum, the re¬ 
semblance of cases and leaves being quite remarkable. I have 
the larvae and pupae from a stretch of the Yahara River where it 
leaves Lake Monona, and from University Bay. 
The adults were observed on July 9, in the bushes and trees 
along the above mentioned stretch of river, literally by thou¬ 
sands. The number present can only be compared to the hordes 
of Mav-flies so often observable. 
(PI. LIII, Fig. 5. PL LIX, Figs. 10-18.) 
