1863.] 
197 
space about as wide as the orbit of the the posterior ocellus.—Species, 
vittigera Walsh, qiiadripunctata n. sp. 
Hexagenia n. g. Wings four, hind wings wide, all with numerous 
cross-veins; costal cross-veins in the front wing numerous, never absent 
on the middle of the costa. First tarsal joint distinct in the anterior 
legs % 9 , indistinct and connate in the four posterior legs h 9 , in all 
the legs shorter than the 2nd tarsal joint; anterior tibia S much longer 
than the femur; anterior % legs very long, much longer than anterior 
9 legs; all the other % 9 legs short, the hind legs not attaining the 
tip of the abdomen. Two long abdominal set*, pilose at the tip under 
the lens, the intermediate seta rudimental. Eyes % separated by a 
space about twice as wide as the orbit of the posterior ocellus.—Species, 
hilineata Say, limhata Pictet. 
Heptagenia n. g. Wings four, hind wings wide, all with nume¬ 
rous cross-veins ; costal cross-veins in the front wing numerous, never 
absent on the middle of the costa. First tarsal joint distinct and 
free in all % 9 legs, never longer than the 2nd tarsal joint; anterior 
tibia h but slightly longer than the femur; anterior % legs generally 
very long, and generally much longer than anterior 9 legs; all the 
other legs long, the hind legs much more than attaining the tip of the 
abdomen. Two long, glabrous set*; no intermediate seta. Eyes % 
separated by a space at least as wide as the orbit of the posterior ocel¬ 
lus.—Species, flavescens Walsh, mterpunctata Say, pulchella Walsh, 
terminata Walsh, simplex n. sp., cruentata n. sp., maculipennis n. sp. 
Pentagenia n. g. 
P. VITTIGERA Walsh. The 9 differs in no material respect from 
the S . In the % , as well as 9 5 the costa of the front wings is tinged 
with yellow, and instead of saying “ abdomen piceous, &c., &c,, &c., 
half-way to its tip,’’ I should have said, “abdomen piceous on the cen¬ 
tral J or f of the dorsum, the piceous vitta on each segment hav¬ 
ing its sides nearly straight, except that they are a little convergent 
behind, and having also two narrow yellowish divergent basal vitt* 
extending half-way to its tip.” The eyes % in life are yellow on 
their upper | and dark ferruginous on their lower I ; and in all % 9 
legs tarsal joints 2 — 4 regularly and but moderately diminish in length. 
—Length % 17—18 mill. 9 16 mill. Exp. % 30—32 mill. 9 36 mill. 
