RHYACOPHILIDE. 
Periop oF EMERGING.—The species is found as larve, pupee, 
and adults during the entire summer. 
DEscRIPTION OF Larva.—Length, 9 mm. In cross-section 
the body is round. It assumes a curved position, especially marked 
toward the caudal end of the abdomen. 
GLOSSOSOMA AMERICANUM. 
193. Larva. Head and thorax. 196. Case of larva, dorsal view. 
194. Larva. Frons. 197. Case of larva, ventral view. 
195. Larva. Mandible. 
Head.—The head is small compared to the thoracic segments. 
It is light-brown without a pattern, except a light-colored area 
around each eye and indistinct muscle-attachment marks. The 
mandibles, figure 195, are alike; each has a sparse fringe of pale 
hairs on its inner margin; in color they are brown. The labrum 
is shown at the base, with pale outer margins which bear numerous 
short, light-colored hairs. 
Thorax.—The prothorax, figure 193, is heavily chitinized 
above; it is nearly uniform brown in color; on the ventral side 
there is a brown chitinous plate covering the entire lower surface 
of the segment; the horn is absent. 
The meso- and meta-thorax are without chitinous dorsal plates. 
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