AQUATIC INSECTS IN THE ADIRONDACKS 523 



1895-97 Diplas vicina Calvert, N. Y. ent. soc. Jour. 3 : 48 and 5 : 94 (listed 

 from Lake St Re^is, Keeseville, Dobbs Ferry, New York^ Ithaca, Cats- 

 kill mountains, Schoharie, Piseeo lake and Buffalo) 



1899 Diplax vicina Kellicott, Odon. Ohio, p. 110 (description aud figure) 



1900 Diplax vicina Williamson, Dragon flies Ind. p. 323 



This pretty, little, yellow-legged, autumnal species is likely to be found 

 about every marsh-bordered pond in the state. It flits about the shore 

 vegetation and is not at all difficult to capture with a net. At Cascadilla 

 pond near Ithaca I have watched the females ovipositing on beds of wet 

 and matted dwarf club-rush, sometimes alone, but oftener held by the 

 male, both descending together and rising every time the tip of the ab- 

 domen was brushed against the wet mats. Some eggs obtained in Sep- 

 tember at Ithaca hatched the following January, having been kept the 

 while in a laboratory of the normal temperature. Doubtless, under nor- 

 mal conditions they do not hatch before spring. 



Nymph. Total length 13 mm; abdomen 8 mm; hind femur 4.5 

 mm; width of head 4.5 mm, of abdomen 5 mm. 



The eyes are a little more prominent laterally than in other members 

 of the genus; the lateral setae are nine; mental setae about 12 or 13, 

 the fifth (counting from the side) longest; the movable hook is exces- 

 sively long and slender; the superior appendage is one third shorter than 

 the inferiors, and the laterals less than one half as long as the inferiors. 



At Saranac Inn, the nymphs were found at the north side of the outlet 

 of Little Clear pond, on the shelving bank behind the hummock of cat- 

 tails. They are rather daintily colored with bands of black across the 

 head, including the eyes, around the femora, and across the middle of 

 the abdominal segments. They clamber about amid the semiaquatic 

 vegetation. 



Sympetrum semicinctum Say 



Figure 30 



1839 L i bell ul a semicincta Say, Acad. nat. sci. Phil. Jour. 8 : 27 

 1861 Diplax semicincta Hagen, Synopsis Neur, N. Am. p. 176 

 1893 Diplax semicincta Calvert, Am. ent. soc. Trans. 20:263 (descrip- 

 tion and figure) 

 1895 Diplax semicincta Calvert, N. Y. ent. soc. Jour. 3:48 (listed from 

 Ithaca, Staten Island, Westchester co.) 



1899 Diplax semicincta Kellicott, Odon. Ohio, p. 110 (description aud 



figure) 



1900 Sympetrum semicinctum Williamson, Dragon flies lud. p. 324 



(description and figure) 



This species, which I have observed at Ithaca, and have bred in Illinois, 

 did not appear at Saranac Inn. It is quite like the others of the genus. 

 I have observed the female ovipositing alone in muddy pools among 

 dead smartweed stems on a mud flat beside a pond. 



