NORTH AMERICAN CADDIS-FLY LARVZ. 
ments three, four, and five, there is a transverse elliptical ring 
of chitin. The gills, figure 118, are weak and of varying number. 
DESCRIPTION OF THE CasE.—The case of the mature larva is 
about ten millimeters in length. It is constructed of small or 
minute sand grains, firmly cemented together in the form of a 
slightly flattened and slightly curved tube. On each end of the 
tube the larva cements one or more heavy “ballast” stones, figure 
120. 
NEOPHYLAX AUTOMNUS. 
LarvAL Hasirs.—The larve are found in spring basins and 
in spring streams near their sources. In the McLean region they 
are especially abundant in Big Spring and its outlet for a few hun- 
dred feet. They do not seem to occur in streams far from their 
sources, nor have they been found where there is any great inflow 
of surface water. These spring streams, in which the larvae 
occur, are swift-flowing, with stony bottoms, and practically void 
of vascular plants and of sticks and surface litter. 
LarvaL Hasits.—In habits the larve do not seem to differ 
from N. difficilis. 
The prepupal behavior, also, is apparently like that of N. 
difficilis. 
Prertop oF EMERGING.—Adults are on the wing from late Sep- 
tember until early November. 
Description oF Larva.—Length (in natural position, with 
head turned under thorax), 7 mm. 
Head.—In form the head, figure 121, is similar to that of N. 
difficilis, except that it is narrower across the cephalic margin. In 
color it is deep mahogany-brown, almost black, except a light- 
colored semi-circular area around the under surface of each eye, 
and some small light-colored spots behind and beneath the eyes. 
On the frons, figure 122, there is a thorn-like projection that is 
plainly visible in profile view. 
Thorax.—The cephalic third of the prothoracic shield, on the 
dorsal surface, is creamy white; behind this light area it is dark 
smoky-gray. The mesothoracic shield is smoky-gray with indis- 
tinct markings, and bordered on the lateral and caudal margins 
with black, as in figure 121. 
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