714 Wisconsin Academy of Sciences , Arts and Letters. 
and legs clear yellow, the head clouded with dark brown in the 
central portion above, with inconspicuous lighter spots and a 
black posterior border. Pronotum with a black posterior bor¬ 
der. Meso- and metanotum unchitinized. Xo tubercles on the 
first abdominal segment, no gills, and no lateral line. Draggers 
long, down-curved. Mandibles unlike. McLachlan ascribes 
gills to the larvae of this genus, but, as noted by Ulmer (1903), 
there are exceptions in the European species, while here we 
have at least one exception in the American species. The larva 
of no other species of the genus has been described in America. 
Pupa. —Length, (in cocoon) 11 mm. Width, 2.5 mm. An¬ 
tennae reaching to the 5th segment. White or reddish-brown. 
On segments 3-7 are very small plates with almost microscopic 
spines pointing backward, and on the posterior parts of segments 
3, 4, and 5 are similar ones, the spines pointing forward. Lab- 
rum shorter than long, rounded, three hairs on either side near 
the base and four near the tip. The mandibles are strong, each 
with three large teeth bearing smaller ones. In my single well 
preserved specimen, there were no special anal appendages, that 
end of the abdomen showing the general shape of the genitalia 
beneath. As there is no opening of the case to be kept clean, 
there is no need for special structures. 
Case .—The larva lives in a loosely built case of gravel, which 
can scarcely be measured accurately. At time of pupation this 
becomes a strong, irregular hemi-ellipsoid, measuring about 10 
mm. wide by 15 mm. long. Within this is a strong brown co¬ 
coon, the dimensions of which are given above. 
Habits and Occurrence .—These larvae are common in the mod¬ 
erately swift parts of the stream in Parfrey’s Glen, where, early 
in Tune, the pupal cases may readily be obtained from the 
stones. As my few specimens (all reared) happen to be fe¬ 
males, a complete description including male genitalia could not 
be attempted. June 10 is the date of the appearance of the 
adults in the laboratory. 
(PI. LIII, Pig. 9. PI. LXT, Pigs. 14-21.) 
Charles T. Vorhies, 
Zoological Laboratory, 
University of Wisconsin. 
May, 1908. 
