Family NEMOURIDAE 
This family consists of the genera Nemoura, Taeniopteryx, 
Leuctra, and Perlomyia. The nymphs are small, for the most part 
under 15 mm. in length, and are almost wholly concolorous. They 
inhabit largely the small upland spring brooks and are herbivor- 
ous in food habits. The life cycle appears to be one year. It is 
rather difficult to assign to nymphs of this family any character- 
istics which will apply to all the genera included. The mouth 
parts are typically herbivorous. The labrum is somewhat wider 
than long and the epipharynx is absent. Mandibles with four 
or five blunt teeth followed by a molar which bears a comb of 
short, stout hairs, and beyond this a group of long hairs. Lacinia 
wide at base, at the apex with two small teeth, and partially 
separated from the stipes by a short incision or suture; maxil- 
lary palpus stout and much longer than galea. Glossae and para- 
glossae of labium almost equally long and at the tips with numer- 
ous papillae. Labial palpi short and stout, and in Taeniopteryx 
and Nemoura usually not extending beyond the tips of the 
paraglossae, while in Leuctra they may extend considerably 
beyond the ligula. 
The wing pads in Taeniopteryx and Nemoura are wide and are 
directed away from the body, while in Leuctra they are narrow 
and le parallel to the body. 
Gills mostly absent. In some species of Taeniopteryx coxal gills 
are present, and some species of Nemoura possess gills in the cer- 
vical region. 
In mature nymphs the venation of the wing pads can often 
be seen clearly, and in many nymphs the genital characters aid 
in identification. 
Genus NEMOURA Latreille 
The nymphs of this genus measure mostly less than 10 mm. in 
body length. They are most easily recognized by the stocky form 
of body, the fringe of spiny hairs around the margin of the pro- 
notum, the spiny legs, and when gills are present they occur in 
the cervical region between the head and the anterior margin of 
the prosternum. 
Head no wider than pronotum; rounded behind, somewhat 
hairy; ocelli noticeable in the more mature nymphs, hind ocelli 
a little closer to the eyes than to each other; antennae about half 
as long as body and composed of less than fifty segments; epi- 
cranial suture distinct. 
