PLECOPTERA NYMPHS OF NORTH AMERICA 17 
maxillary palpus long and slender reaching far beyond the tip 
of the lacinia; the terminal segment tapers to a rather fine point ; 
stipes about as long as lacinia. Labium wide; submentum about 
twice as wide as long; glossae short, triangular; paraglossae large 
and rounded at the tip; both glossae and paraglossae with a few 
tubercles at the tip. 
Perlesta placida Hagen 
(Plate 4, figs. 60-65; Plate 21, fig. 199.) 
Length of body up to 10 mm.; antennae up to 5 mm.; ecerci up 
to 6mm. 
General color yellowish brown, with a tendency toward having 
the entire body covered with small brown dots, giving it a freckled 
appearance. Head a little narrower than the pronotum, yellowish 
with a darker transverse band across the head through the region 
of the ocellar triangle; hind ocelli closer to each other than to the 
eyes; occipital ridge not very prominent but plainly indicated by 
a series of very short hairs, and by brown markings; antennae 
long and slender and composed of at least fifty segments. 
Pronotum at least twice as wide as long; front margin convex, 
hind margin nearly straight; angles broadly rounded; surface 
slightly rugose, yellowish brown with lighter areas on the lateral 
margins and along the middle of the anterior and posterior mar- 
gins; a shallow groove extends around entire pronotum; sides 
of pronotum with rather wide flanges; surface quite hairy, with 
rather long hairs all around the margin; meso- and metanotum 
very broad, sides usually much rounded. 
Legs flattened; femora and tibiae fringed with long hairs; 
first and second tarsal segments short, subequal, the two together 
less than half as long as third segment. Abdomen depressed ; sur- 
face hairy; posterior margin of each segment with a row of 
spinules. Cerci long and slender and composed of about twenty- 
five segments, the ones beyond the middle very long. 
Seven pairs of branched gills; two pairs on the prothorax at 
the outer base of the legs; two double pairs on the mesothorax, 
the first at the antero-lateral margin of the mesosternum, the 
other at the outer base of the legs; two pairs on the metathorax, 
the first at the antero-lateral margin of metasternum, the other 
at the outer base of the legs. One pair of anal gills. 
The nymphs are carnivorous and occur mostly in swift water. 
This species is widely distributed over the Central and Eastern 
States. 
