250 NEW YORK STATE MUSEUM 
Nymph. Measures in length 12mm, gills 4 to 4.5mm addi- 
tional; width of head 2.5mm. Color greenish, with faint brown- 
ish rings on the femora and five pairs of indistinct spots ranged 
along the margins of each gill lamella. 
Head much wider than long, strongly narrowed behind the 
very prominent eyes to well rounded hind angles, whose curve 
is exactly the reverse of the concavity of the excavation of the 
hind margin between the hind angles. Legs slender, smooth; 
wing cases reaching the middle of the fourth abdominal seg- 
ment. Gills [pl.15, d] lanceolate, pointed, widest a little beyond 
the middle, with more or less distinct small, marginal spots. 
Antennae six jointed, the six joints having the following 
relative lengths:—1:2:3:2:1.7:2. Labium slender, the hinge 
reaching posteriorly about to the bases of the middle legs.. 
Mentum not abruptly narrowed to the hinge, but with the 
lateral margins somewhat sinuate in outline. Mental setae ft 
(and a rudiment) each side; lateral setae six each side. The end 
of the lateral lobe [pl.14,7] above the end hook not denticulate 
as in all the other genera. 
Nehallennia gracilis Morse 
1895 Nehallennia gracilis Morse, Psyche, 7:274 
This species, hitherto reported from but two localities in 
Massachusetts, was common at Saranac Inn about the edges of 
Little Bog pond, where it was associated with N. irene, 
Lestes eurina, L. uneata, Cordulia’ Sime 
leffi, and Dorocordulia libera, a notable assem- 
blage of bronzy greens. It swarmed about the edges of the 
clumps of lambkill, and could be taken anywhere by sweeping 
with a net the sedges and cotton grass that grew on the sphag- 
num beds. I regret I did not observe at the time that I was col- 
lecting anything but N. irene; and, having already bred that 
species, I made no effort to get the nymph of this one. 
ENALLAGMA 
This is the dominant genus among our Zygoptera. Twelve 
species have been recorded hitherto from the State; two other 
species (piscinarium and pollutum) are here recorded, 
and several other species are regional. These frequent all sorts: 
of fresh water, being most abundant where there is much sub- 
merged and floating vegetation. They dwell in still and shallow 
water. 
