68 THOMAS SAY FOUNDATION 
and brown between the ocelli, extending back to the posterior 
margin of the head. Ocelli large, the distance between them about 
as great as the diameter of a single ocellus; a sharp occipital 
ridge extends across the entire head to the outer margin of the 
eyes, and bears a group of hairs at the'postero-lateral angles. 
Antennae yellowish, of about seventy-five segments; surface of 
head quite smooth. 
Pronotum twice as wide as long; front margin somewhat con- 
vex, hind margin very slightly concave in the center, sides con- 
vex, front angles more narrowly rounded than hind ones; middle 
portion of pronotum yellow, bordered by brown, and the lateral 
margins, as well as most of the posterior margin, yellow; surface 
of pronotum smooth, the margins bordered with short hairs. 
Meso- and metanotum brownish with middle field and the apical 
half of the wing pads yellow. Legs yellow, the femora and tibiae 
with a fringe of hairs. 
Abdomen somewhat flattened; banded with yellow and brown, 
the basal half of each segment brown, and the distal half yellow; 
posterior margins of segments bordered by a fringe of short 
spinules; caudal gills about as long as tenth tergite; cerci yellow, 
of about forty segments, each segment terminating in a whorl 
of hairs. 
This species was reared by Dr. C. Betten some years ago, the 
adult emerging on July 11. It was reared by the writer in 1927, 
emerging on July 3. Both specimens are from Ithaca, New York. 
The nymphs are found in the quieter pools in freshwater streams. 
They are carnivorous, and feed apparently largely upon insect 
larvae. 
Genus CLIOPERLA Needham and Claassen 
The nymphs of this genus, when fully grown, measure not much 
over 15 mm. in body length. The general color, as far as is known, 
is brown, or a combination of yellow and brown, as in C. clio. 
Head a little wider than pronotum; three ocelli, the hind ones 
about as close, or a little closer, to the eyes than to each other; 
epicranial suture distinct; occipital ridge absent; antennae about 
half as long as the body. 
Pronotum transversely oval; about twice as wide as long; 
marginal groove distinct in front and rear, but indistinct on the 
sides. Wing pads well developed and elongated; front wing pads 
lying almost parallel to the body, and sinuous on the lateral 
margins; hind wing pads directed slightly outward. Legs rather 
