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 [pi. 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 1 

 (and a rudiment) each side; lateral setae six each side. The end 

 of the lateral lobe [pl.l4, i] 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. uncata, Cordulia shurt- 

 1 e f f i , and Dor o cordulia 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. 



This is the dominant genus among our Zygoptera. Twelve 

 species have been recorded hitherto from the State; two other 

 species (piscinarium and p o 1 1 u t u m) are here recorded, 

 and several other species are regional. These frequent all sort» 

 of fresh water, being most abundant where there is much sub- 

 merged and floating vegetation. They dwell in still and shallow 



water. i ' ,' ; 



