454 
NORTH AMERICAN PLECOPTERA 
Male. The ninth ventral segment slightly produced, forming a short sub- 
genital plate, the posterior border somewhat thickened; two longitudinal 
carinae divide the plate into three fields, the middle one narrower at tip than 
base, the lateral areas deeply hollowed. The tenth segment very narrow below; 
bifid above, a wide cleft separating the two rounded lobes, each with a small, 
oval, homy area at the base. The sub-anal plates spoon-shaped and clasping 
the ba<se of the supra-anal plate, which is modified to form a short, stout, erect 
probe (fig. 14). 
Female. The entire eighth sternite involved in the formation of the vulvar 
lamina; a deep median cleft divides the segment into two flat, obtuse processes, 
whose opposed edges are straight at the base, concave in the apical half, and 
the outer edges, convex (fig. 10). 
Two males, one from Black Mountains, North Carolina, and 
the other (alcoholic) from Ithaca, New York, May, 1891, and one 
female without locality data. 
Newman’s type specimen is in the British Museum, London. 
Nymph 
I am placing this undescribed nymph here tentatively since it 
was found in the same general region in which the adult occurs, 
and since it is similar to the nymph of Pt. proteus Newman, — 
the adults of the two species being closely allied. The general 
color is perhaps a little darker than Ft. proteus, and the posterior 
angles of the prothorax may be a little more produced (fig. 18). 
The chief difference, and the only one recognizable without the 
two for comparison, is in the lateral hooks on the abdomen. In 
Pt. biloha they stand well out from the body, the posterior and 
lateral edges being about equal in length, and the hooks on the 
seventh and eighth segments are as prominent as those on the 
preceding segments (fig. 26). In Pt. proteus the hooks are close 
to the body, and those on segments seven and eight are small 
and inconspicuous. 
A number of immature female specimens from Virginia (Mac- 
Donald) are in hand. 
Pteronarcys comstocki new species 
1838. 9 Pteronarcys proteus Newman, Ent. Mag., 5: 177. 
1839. 9 Pteronarcys proteus Newman, Mag. Nat. Hist., 3: 34. 
1873. 9 Pteronarcys proteus Hagen, Proc. Dost. Soc. N. H., 1.5: 281. 
1907. 9 Pteronarcys proteus Klapdlek, Bull. Internal. Acad. Sci. Bohfime, 
12, p. 7 of reprint. 
