Vorhies—Studies on the Trichoptera of Wisconsin . 707 
Case. —Length, 15-20 mm. Width, 8-10 mm. at the anterior 
end. This case, typical of the genus, is formed of sand with 
lateral extensions of coarser particles of stone, and with a large 
anterior dorsal hood, completely protecting the larva as it feeds. 
The pupa (in the laboratory) lies in a case formed by the 
closure of the ventral opening at the anterior end, a vertical slit 
being left at the posterior end. My specimens, unfortunately, 
do not show the nature of the opening at the anterior end, the 
few at hand being such as the pupa have cut in making their 
escape. The cases in aquaria were slightly buried in the sand. 
Habits and Occurrence .—These larvae are rather common and 
yet often difficult to get, owing to the form of their cases and 
their bottom habits. On a sandy bottom they are very difficult 
to see unless they chance to be moving. One spring they were 
found in numbers, in May, on mussels which were being dredged 
up for class use, but so many have never been obtained at one 
time since. Betten (1901) reports M. cinerea from flowing 
water only; all of my specimens of uniophila are from the lakes, 
some from a depth of 10-12 feet. I have them from Lakes 
Mendota and Monona, and from a small lake near Minocqua, 
in Oneida County, Wis. 
The pupal stage is of two weeks, or less duration. Adults are 
common in June and July. Their peculiar resting position is 
well shown by Betten’s illustration of cinera f (1901) PI. 13, 
Fig. 4. I have specimens from Madison and from Trout Lake, 
Vilas County, Wis. 
(PI. LIII, Fig. 6. PL LVII, Figs. 11-19.) 
HYDROPS YCHIDiE. 
Hydropsyche aliernans Walker. 
Philopotamus alternans Walker, Brit. Mus. Cat. Yeur., 1852, 
104. 
Philopotamus indecisa Walker, Brit. Mus. Cat. Yeur., 1852, 
104. 
Hydropsyche indecisa Hagen, Syn. Yeur. Y. Am., 1861, 288; 
Verh. zool.-bot. Ges. Wien, XIV, 1864, 822. 
