AQUATIC INSECTS IN THE ADIRONDACKS .503 



casionally one would sweep out into the forest and disappear among the 

 hemlocks. 



The nymphs obtained were gathered from a shaded trashy place in the 

 edge of Little Clear pond and from Bone pond. They lie sprawling 

 amid the trash after the manner of the better known Libellulas. 



I did not rear these nymphs, the season of their transformation being 

 over, apparently, before I obtained any of them. I kept a few in a cage 

 through the greater part of the season : nevertheless, there is not the 

 slightest doubt as to their identity. They agree very closely with the 

 nymphs of the European C. aenea Linn., with specimens of which I 

 have compared them. Male nymphs show in the stretched skin of the 

 superior appendage the forked tip of the inferior appendage of the imago. 

 The nymphs, like the imagos, were in numbers second only to the Tet- 

 ragoneurias among the Saranac Cordulinae. 



Nymph. Total length 21 mm; abdomen 12mm; hind femur 6.5 

 mm; width of head 6 mm, of abdomen 7 mm. 



Body elongate, sparsely fringed with coarse hairs on the appendages, 

 edge of frons, rear of head, and lateral margins of abdomen; color 

 greenish brown marked with blackish brown as follows : a tranverse 

 band across the head including the eyes (almost divided by the median 

 yellow ocellus when the nymph is grown) an urceolate median band on 

 the prothorax not attaining its front margin, and divided by a fine yellow 

 median line; a broad oblique lateral yellow band extending from above 

 the base of the fore leg to the middle of the hind wing; below the last, a 

 narrower parallel stripe above the base of the hind leg ; a pair of sub- 

 median rows of blotches on the abdomen extending posteriorly from 

 beneath the tips of the hind wings; and rings on femora and tibiae. 



Head with the eyes laterally prominent and well rounded, hind angles 

 obtuse and the hind margin slightly concave; no vertical tubercles; 

 frontal ridge low obtuse; labium reaching posteriorly between the 

 bases of the second pair of less, triangular elongate, channeled above ; 

 median lobe prominent, declined; mental setae about 14, regularly 

 graduated in size, the fourth (counting from the side) longest; lateral 

 setae seven ; movable hook hardly longer than the setae, nearly straight ; 

 teeth about nine, low, crenate, increasing in breadth inferiorly, each with 

 several spinules. 



Abdomen oblong, a little widened to the seventh segment, most 

 narrowed apically on the ninth segment; loth segment annular, half as 

 wide as the ninth, and one fourth to one third as long as the ninth is on 

 its middorsal line; ninth segment one half as long on the middorsal line 

 as on the midventral ; appendages almost equal, the superior and the 

 laterals successively a very little shorter than the inferiors, which are 

 about as long as segment 9 is on its dorsal side; lateral spines on 

 segments 8 and 9 very short (about one fifth the length of the body of 

 the segments which bear them), but pyramidal. 



The first cast nymph skin was obtained June 16. The imagos were 

 flying commonly throughout the montli of July. 



