AQUATIC INSECTS IN THE ADIRONDACKS 



505 



flight than that species, but they dash along shore on shining, transparent 

 wings, dancing in and out of the httJe coves in the edge of the sphagnum 

 fringe, and once in a while are seen resting on the tall summit of some 

 pitcher plant flower. 



The one nymph I obtained was taken from the edge of Little Clear 

 pond at the outlet, and was reared, transforming July 7. From that 

 cast skin the following description of the nymph was drawn up. The 



ail* ? 



Fig. 28 Dorocordulla, end of abdomen, a, & and c of D. libera Sel.; x, y and 5r D. lepida 



specimen is in the New York state collection at Albany. The study of 

 this specimen, which was preserved and labeled by myself with such 

 promptness and care as to preclude error or confusion of species among 

 my specimens, reveals an error in Cabot's work on the corduline nymphs. 

 The one he described asSom. libera, raised, can not have been of 

 that species. I have not seen his specimen, but both his description and 

 his figure disagree utterly with my specimen. They agree quite well with 

 the nymph ofHelocordulia uhleri, and I think they may have 

 belonged to that species or to H. s e 1 y s i . 



Nymph. Total length 21 mm; abdomen 11 mm; hind femur 

 6 mm; width of head 5.5 mm, of abdomen 7 mm. 



Very similar to the nymph of C. s h u r 1 1 e f f i , but smaller, and with 

 the black band across the head broader between the eyes, the eyes them- 

 selves more prominent laterally, and the hind angles of the head more 

 angulate; labium similar; lateral setae seven; mental setae 12-13, ^^^h 

 side, the fifth (counting from the side) longest, the others regularly 

 grading up to it; abdomen similar, but the very rudimentary dorsal 

 hooks a little more prominent on the middle segments (perhaps a little 

 less obscured by tufted hairs about them) ; lateral spines longer on 

 segments 8 and 9, about a third the length of their respective segments; 

 inferior appendages longer than the superior, which in turn is longer 

 than the laterals. 



