64 THOMAS SAY FOUNDATION 
Abdomen subeylindric; posterior margin of each segment with 
a fringe of short stiff hairs which become more numerous with 
each succeeding segment. 
Mouth parts. Labrum about three times as wide as long with a 
fringe of hairs on the anterior margin. Mandibles nearly twice as 
long as wide; slightly asymmetrical; left one with five unequal 
teeth, the right one with four distinet teeth, and with an indica- 
tion of a small fifth one; the teeth followed by a row of long 
hairs. Maxillae: lacinia wide at the base, a single, large, ineurved 
terminal tooth followed by a series of long hairs. Galea eylindrie, 
reaching almost to the tip of the lacinia, and one or more long 
hairs at the tip. First and second segment of maxillary palpus as 
wide as long, or wider, third segment a little longer than one and 
two together ; fourth nearly half again as long as the third, and 
with the inner apex produced and covered with long hairs; fifth 
segment less than half as long as fourth, and considerably less 
than half as large in diameter, bearing at the tip a small tubercle 
and a few hairs. Labium: glossae very small, triangular; para- 
glossae large, with a few long hairs on the dorsal surface. First 
segment of palpus longer than wide, second half again as long 
as the first; third a little more than half as long as the second, 
and hardly more than half as large in diameter; the apical seg- 
ment with a small tubercle, as in the maxillary palpus. Hypo- 
pharynx closely beset with short hairs at the tip. 
The above description has been drawn from the cast skin 
of a reared nymph taken at Ithaca, N.Y. This species is common 
in the Eastern States. 
Genus PARAPERLA Banks 
The nymphs of this genus, of which only a single species is 
known in western North America, are recognized by the slender 
body; long head with small eyes set far forward, so that the 
distance from the eyes to the hind border of the head is twice as 
great as the diameter of the eyes; a transversely oval pronotum ; 
and absence of gills. 
Color yellowish; surface of head and thorax smooth. Head 
slightly wider than pronotum; three small ocelli. Pronotum oval, 
wider than long; marginal groove continuous all around; sides 
and angles rounded. Legs sparsely fringed with hairs; first and 
second tarsal segments very short, subequal. Wing pads broad, 
and rounded on the lateral margins. Abdomen nearly cylindrical ; 
cerci short and stout. 
