712 Wisconsin Academy of Sciences, Arts and Letters. 
head, prothorax and legs straw yellow, no markings except the 
posterior half of the lateral border, and all the posterior border, 
black. Meso- and metathorax unchitinized, except lateral black 
bars for attachment of legs. No gills, the lateral line almost 
indistinguishable. The 9th abdominal segment is small, the 
prolegs long and slender, with a strongly curved hook. The 
labium is extremely elongated, the silk duct opening at the tip, 
however. Mandibles unlike as to teeth, each with a very dense 
brush of black hairs within, rounded teeth on the outer sides. 
Pupa. —Length, 12-15 mm. Width, 2 mm. Antennae ex¬ 
tend slightly beyond the 4th abdominal segment in the female; 
as long as the body in the male. Color in life yellowish. Well 
developed spines pointing backward occur on segments 3-8, the 
number in each place being 3-5. On the posterior part of the 
5th segment is a pair of plates bearing 3-6 forwardly directed 
spines. The 9th segment ends in a pair of stout processes with 
brushes of dark hairs distally, and on either side of this segment 
occurs a short, stout process also bearing a brush of dark hairs. 
Labrum small, with 12 long black hairs. Mandibles with broad 
base, the distal portion slender, cylindrical, curved, without 
teeth. 
Case. —The larva lives in a non-portable abode, in this respect 
resembling other Hydropsychidse. It burrows into the sand of 
the bottom of the stream and forms a long, often complexly 
branched case of sand, scarcely firm enough to keep its shape 
when it is extracted from its position. This case, about 5 mm. 
in diameter, excepting some smaller branches, is often as much 
as 65 mm. in length, the greater portion buried, only 10-20 
mm. projecting from the stream bed. When the whole case is 
taken out carefully (a difficult task) a more or less distinct 
swelling, usually nearer the submerged end, is visible, in which 
the pupa is found. Anteriorly this part is closed by a membrane 
of peculiar weave, the openings being very small and irregular, 
the thread dark, so that it has somewhat the appearance of co- 
coanut fiber. At the posterior end is a bag of similar appear¬ 
ance, slightly tapering, and about 5 mm. in length, in the end 
of which the exuviae are retained. Since the lower part of the 
case is embedded in the sand the outward flow of water must be 
