526 NEW YORK STATE MUSEUM 



PACHYDIPLAX 



There is a single species. 



Pachydiplax longipennis Burmeister 



1839 Libellula lougipeunis Burmeister, Handb. eut. 2 : 850 

 1861 Mesothemis longipennis Hagen, Synopsis Neur. N. Am. p. 173 

 1893 Pachydiplax longipennis Calvert, Am. ent. soc. Trans. 20 : 265 

 1895-97 Pachydiplax longipennis Calvert, N. Y. ent. soc. Jour. 3 : 48 

 and 5 : 94 (listed from New York, Westchester eo., Ithaca and Black- 

 rock) 



1899 Pachydiplax longipennis Kellicott, Odon. Ohio, p. 114 (descrip- 



tion) 



1900 Paehy d iplax longipennis Williamson, Dragon flies Ind. p. 326 



(description) 



This is a species of very wide distribution. It has been recorded 

 from most regions of North America, south of the Canadian, from 

 Mexico, and from the Bahama islands, and last summer Dr O. S. West- 

 cott, stopping to visit our station on his return from the Bermuda islands, 

 brought a number of specimens collected in that new quarter. The 

 species was not observed at large at Saranac Inn. It is likely to be 

 found rather generally distributed throughout the state at lower alti- 

 tudes. 



Images of this species are swift of wing, and somewhat difficult to 

 capture with a net. The males hover near the surface of the water, 

 darting hither and thither, meeting every newcomer, perching on a twig 

 and immediately quitting it; and, when two males meet in combat, they 

 have the curious habit of darting upward together into the air and flying 

 skyward, often, till lost from view. The females are less in evidence. 

 They rest habitually, except when foraging or ovipositing on trees back 

 from the shore. When ovipositing over open water, they have a curious 

 habit which I have not observed in other dragon flies : they do not rise 

 and descend again between strokes of the end of the abdomen against 

 the surface of the water, but fly along horizontafly close to the surface 

 and from time to time strike downward with the abdomen alone, pre- 

 sumably washing off the eggs. In the midst of vegetation, however, they 

 fly down and up again, as do other species. 



The nymphs clamber about among the trash, and, when grown, trans- 

 form within a few inches of the margin of the water, if suitable place be 

 found so near ; otherwise they may go a distance of se^^eral feet. They 

 are smooth, generally of dark color, with little pattern of color showing, 

 except in the transverse banding of the femora. 



