668 Wisconsin Academy of Sciences, Arts and Letters. 
the posterior half of the 6th segment and forms a loop under 
the 8th. In my single specimen the gills appear to be the same 
as in the larva. Posterior end of the abdomen ending in two 
lpng projections with three hairs on the distal portion. Man¬ 
dibles long, length and breadth sub-equal, provided with a brush 
of five long hooked bairs on either side. 
Case. —Length, 20-30 mm. Width, anterior, 3 mm.; pos¬ 
terior, 2 mm. Composed of flat pieces of plant material, ir¬ 
regularly placed, not with a spiral arrangement. Usually with 
one or two pieces projecting at the anterior end as a dorsal hood. 
Habits and Occurrence .—The larva of this species is found 
only in the more shallow pools, which are subject to drying out 
so as to contain but little water in the fall, and, one would sup¬ 
pose, to freezing solid in the winter. Two specimens were 
secured in spring from a small pool scarcely six inches deep. 
Pools in which the phyllopod crustacean, Branchipus, may be 
taken, are of the right kind for this species. Early in April 
many larvae of various sizes, most of them quite small, may be 
obtained by sweeping lightly over the vegetation with a small 
meshed net. 
Though a most careful search was made at intervals during 
the time between the finding of the larvae in abundance and the 
appearance of the adults, the pupae could not be located in their 
natural habitat. In the laboratory, pupal cases were closed 
May 9, and the first adult appeared on May 23. Previous to 
this, on May 13, two specimens taken with a trap lantern, 
proved to belong to this species. These must have come some 
distance, as it is at least a mile from Science Hall, where the 
trap was operated, to any pool suitable for the larvae. On two 
different occasions I discovered imagos in the house, equally dis- 
