PLECOPTERA NYMPHS OF NORTH AMERICA 115 
a feeble coating of fine hairs; epicranial suture distinct; hind 
ocelli about twice as close to the eyes as to each other; antennae 
with about forty-five to forty-six segments. 
Pronotum a little longer than wide, widened posteriorly ; front 
angles more narrowly rounded than hind ones. Meso- and meta- 
notum hairy, without wing pads in the male, or with only very 
small rudiments; female with conspicuous wing pads, although 
they are rather wide and short. 
Abdomen eylindrical. In the male, the tenth tergite is pro- 
duced into a prominent protuberance which is directed slightly 
upwards; in dorsal view this protuberance is broadly rounded at 
the tip but in side view it is rather square at the tip or roughly 
boot-shaped. In mature nymphs the genital structures of the 
developing adult may readily be observed. Cerei with twenty- 
seven to twenty-eight segments. 
Frison (6) has questioned my statement (3), that this species 
is viviparous. Although I have no experimental evidence to con- 
firm my statement, I have again checked over the material and 
find that in some of the females there occur fully formed nypmhs, 
with their bodies completely extended, and measuring 1 mm. in 
length. Frison suggests ‘‘the possibility that the nymphs observed 
by Claassen in a dissected female were disclosed by the accidental 
rupture of the egg shell.’’ However, the young nymphs were first 
noted in the alcoholic female specimens underneath the abdomi- 
nal wall before any of the specimens had been dissected. In these 
females the anterior portion of the abdomen contained eggs only 
while in the posterior part a number of fully developed nymphs 
could be clearly observed. Dissection dislodged eggs and nymphs 
and the eggs were not brittle or easily ruptured. Frison found 
some of the females laying eggs under laboratory conditions and 
he says ‘‘it was found that the embryonic nymphs of this species 
(wipara) are in a rather advanced stage when the eggs are laid.’’ 
Lake Forest, Oakwood, and many other localities in Illinois. 
Allocapnia incisura Claassen 
Of this species no males have been reared. I have, however, 
several adults, both males and females, in which some of the 
females still have the nymphal skin attached to their bodies. These 
specimens bear the following label: ‘‘ Adults reared in labora- 
tory, taken from aquaria; 15 Jan. 1909. Larvae collected 20 Dee. 
1909, Charleston, Ill. Sta. 57. No. 1201. T. L. Hankinson.’’ 
These nymphal skins are in such poor condition that it is im- 
possible to make an adequate description of the nymph. 
