, AQUATIC INSECTS IN THE ADIRONDACKS 535 



This species occurred sparingly at Saranac Inn. A few images were 

 seen sitting on twigs which rose directly a few feet out of the water. 

 They were shy and difficult to capture, and, when disturbed, would rarely 

 return to the same vicinity. I have not been able to find this so common 

 species in its immature stages in person, but I have nymphs sent me from 

 Ellenville N. Y, by Chester Young, and others from the state of Wash- 

 ington; these agree well with specimens from France which I have 

 received from my esteemed correspondent, M. Rene Martin, of Leblanc. 

 The nymph of this species has long been known in Europe. 



Nymph. The largest Ellenville nymph, apparently full grown, meas- 

 ures in total length 26 mm; abdomen 18 mm; hind femur 6 mm ; width 

 of head 6 mm, of abdomen 8 mm. 



The head is very compact in this nymph, scarcely narrowed behind 

 the eyes ; the median lobe of the labium is produced at the middle of its 

 free border into a flat, toothlike prominence ; lateral setae seven ; mental 

 setae about 13, of which the seven outermost are longest; movable 

 hook slender and incurvate ; the dorsum of the body is scurfy hairy (hardly 

 less so than in L. pule hell a, described below), and the hairs partly 

 obscure the dorsal hooks which are present on segments 3-8 of abdomen, 

 that of the eighth segment short and rudimentary ; lateral spines very 

 short; segment 10 about half as long on the dorsal as on the ventral 

 side ; appendages fully as long as the last two abdominal segments. 

 The laterals have unusual length for a member of this genus in being 

 but about one fourth shorter than the others. 



Libellula semifasciata Burmeister 



Plate 23, flg. 1 



183t> L ib e llula semifasciata Barmeistcr, Handb. ent. 2 ;862 

 1861 Libellula semifasciata Hagen, Synopsis Neur. N. Am. p. 151 

 1839 Libel lu la ternaria Say, Acad. nat. sci. Phil. Jour. 8: 21 

 1842 Libellula maculata Rambur, Jus. Neur. p. 55 

 1893 Libellula semifasciata Calvert, Am. ent. soc. Trans. 20 : 258 

 1895-97 Libellula semifasciata Calvert, N. Y. ent. soc. Jour. 3 : 47 and 

 5 : 94 (listed from New York, Dobbs Ferry and Buffalo) 



1898 Lib ell ula semifasciata Needbam, Outdoor studies, p. 55, fig. 54 



1899 Libellula semifasciata Kellicott, Odon. Ohio, p. 100 (descrii)tiou) 



1900 Libe Hula semifasciata Williamson, Dragon flies Ind. p. 332 (de- 



scription) 



In the north this species is the earliest of the genus to be abroad in 

 the spring, making its> appearance before the middle of May. I have 

 oftenest found the imago about woodland brooks — rarely about ponds. 

 I have never found the nymph ; it is still unknowm. 



