34 
Nasieschna pentacantha Ramb. 
The nymph of this species was doubtfully referred by Gar- 
man (’90, p. 178) to Epiewschna heros. It differs from all Amer- 
ican eschnids hitherto described in the possession of dorsal 
hooks on the 8th and 9th abdominal segments, having the form 
of a median carina terminating in a posteriorly projecting tooth. 
In aspect and habits this interesting nymph is very peculiar. It 
is rough, blackish, and very sluggish, and clings to dead branches, 
roots, or driftwood in quiet water. Doubtless it depends, as 
Mr. Garman suggests, on its obscure color and slow movements 
for escaping detection. Examples were taken by Mr. Hart in 
April and May on branches in dead water and along the banks 
of a slow-flowing stream near Urbana, and also a very young 
one in August in a muddy remnant of a temporary stream in 
Perry county, in southern Illinois. Mr. Garman’s specimens 
were from a muddy slough of the Mississippi near Quincy. Out- 
side of Illinois the imago has hitherto been reported only from 
New York (June), Louisiana, and Texas. Mr. Needham saw 
one taken at Wellesley, Mass. In Illinois it was taken by Walsh 
at Rock Island; and we have specimens from Urbana, and also 
from Cobden in southern Illinois. An imago was found float- 
ing May 20 in a narrow passage where nymphs were at the time 
quite numerous on dead branches lying in the water. From 
these nymphs adults were obtained up to June 10. Our other 
imagos were taken June 11 and 16. 
In addition to the presence of dorsal hooks, as already stated, 
the nymph differs further from E. heros, as described by Cabot 
(81, p. 80, Pl. L, Fig. 3),in the presence of two pairs of tuber- 
cles upon the head, in the absence of lateral spines on the 4th 
abdominal segment, and in that the two processes above each 
front coxa are of equal length. 
The nymph measures 48 mm.: abdomen, 34 mm.; hind 
femur, 6 mm.; width of abdomen, 8.5 mm., of head, 9 mm. 
The median labial lobe is prominent, cleft, without teeth 
on each side of the cleft. The lateral lobes are squarely trun- 
cate, with the outer angle rounded, their sides parallel beyond 
