AQUATIC INSECTS IN THE ADIRONDACKS 513 



The egg (pi. 19, fig. 8) is oblong oval, at first white, turning brownish 

 gray after a few hours ; its surface is closely beset with minute tubercu- 

 late granulations. The gelatinous envelop is scanty. 



The nymphs clamber about over trashy submerged vegetation ; they 

 cHmb well, but swim very poorly. They are cleaner and less sprawling 

 than the Libellulas. The nymph goes no farther from the edge of the 

 water to transform than is necessary to find a suitable place — generally 

 but a few inches. 



Nymph. Total length 15 mm; abdomen 9 mm ; hind femur 5.5 mm; 

 width of head 4.5 mm, of abdomen 6 mm. 



Head wider than long, sHghtly concave behind, widest across the 

 rounded eyes, which are at the middle of its length; labium (fig. 8A) 

 short, not extending posteriorly beyond the bases of the first pair of legs; 

 lateral setae five; mental setae about nine or 10, the two innermost ones 

 minute and out of line with the others, the fifth (counting from the side) 

 longest ; teeth crenate, well marked, each armed with several spinules ; 

 hook short, httle curved, differing much from the setae behind it in its 

 greater thickness and less length. 



Femora twice ringed with black ; wing cases extending over the sixth 

 abdominal segment. 



Abdomen (fig. 8C) broad, depressed, triquetral, in outline oblong oval ; 

 lateral spines on segments 8 and 9, short; dorsal hooks on segments 3-9; 

 these form a regularly descending curve, and, viewed laterally, look like 

 a segment of a circular saw; superior and inferior appendages equal; 

 the laterals half as long. 



celithemTs 



Two species of this genus, C. e p o n i n a and C. e 1 i s a, are known 

 from this state, and a third, C, o r n a t a, may be looked for toward the 

 coast. These are three of the most beautiful among all our smaller 

 species. Their colors are shades of black, red, yellow and brown ; and 

 the wings in all have a distinct color pattern. 



The nvmphs are known for the two species recorded from the state. 

 They agree in having smooth bodies with depressed abdomen and long 

 lateral spines. The head is wider than long, widest across the very 

 prominent eyes, which at their sides are almost angulate, they project so 

 sharply; the labium is very large, and has numerous very long and 

 slender raptorial setae, and a pair of very long thin movable hooks ; the 

 teeth are almost obsolete, but the spinules which arm them remain. The 

 abdomen is scarcely narrowed posteriorly before the ninth segment, so 

 that the side margins seem to be continued posteriorly in the long spines 

 of that segment. The superior appendage is one fourth, and the lateral 

 appendages are one half shorter than the inferiors. Images and the two 

 known species of nymphs may be separated by the following key. 



