AQUATIC INSECTS IN THE ADIRONDACKS 529 



Then Hagen, in his Synopsis of the Neuroptera of North A7nerica 

 ( 1 861), ranked deplanata and exusta as synonymous (under the 

 later name, however) ; in his Syjiopsis of the Odojiata of America (1875) 

 he ranked them separately, remarking that deplanata was probably 

 but a dwarf southern form of exusta, but he wrote down j u 1 i a as a 

 synonym of exusta. In 1893 Calvert in his Odonata of Philadelphia 

 and vicinity again added deplanata to the exusta lump. The 

 three have been treated as one ever since, and in all recent descriptions 

 and lists, dimensions, coloration, structural characters and distribution 

 are hopelessly confused; and it becomes necessary to revert to the 

 original descriptions to find statement of differences between them. 



The two which concern us here in New York are L. e x u s t a Say and 

 L. Julia Uhler. So far as I am able to judge by my own specimens 

 and by those in the Museum of comparative zoology at Cambridge, these 

 seem to be distinguished by the following characters. 



a Dorsum of the thorax pale with a black stripe each side on the humeral 

 suture, no ante-humeral stripe of white ; the fuscous spot on the base 

 of the hind wing not enveloping the triangle ; the eighth abdominal 

 segment of the male narrower than the seventh ; the apex of the anterior 



branch of the genital hamule of the male directed laterally julia 



aa Dorsum of the thorax blackish brown, with a white ante-humeral stripe each 

 side; the fuscous spot of the hind wing envelops the triangle ; the eighth 

 abdominal segment in the male is as wide as or wider than the seventh; 

 the apex of the anterior branch of the genital hamule of the male is 

 directed posteriorly exusta 



I have described in the Canadian entomologist for 1897 (29 : 144-46) 

 the nymphs of deplanata from Florida. These differ from the 

 nymphs of L. j u 1 i a described below by some unusu- 

 ally good specific characters, such as the entire absence 

 of raptorial setae from the median lobe of the labium, 

 and the hooked teeth on the margin of the lateral lobes. 

 It remains now to discover the nymph of exusta, and 

 to learn whether deplanata agrees with it. 



It will be observed that the characters given in the 

 generic table for nymphs at the beginning of this sub- j,,^ gj ^j^j^ ^^^^^1 

 family abundantly justify the erection of Ladona as JuTiTuhf (to''an'd\* 



. t" • 1 11 1 exustaSay(u) 



a genus separate from L 1 b e 1 1 u 1 a . 



L. e X u s t a is recorded in Calvert's list of the Odonata of New York 

 state from Lake George, and Croton on Hudson. Whether the record be 

 for exusta or for julia, is uncertain. The characters given above 

 will I trust, enable the collector in the future to distinguish between these 



