Dragon -Flies 



When the nymph becomes full grown, it has changed its 

 form from a rather slender creature to a broad and flattened one, 

 not resembling the slender bodied adults in the least. It crawls 

 out of the water on the bank upon the stems of water plants or 

 upon the rocks, and later its skin splits down the back, and the 

 adult dragon-fly emerges. Empty skins of these nymphs are 

 very common objects about watercourses. 



Rather more than two thousand species of dragon-flies have 

 been described, and of these something less than three hundred 

 inhabit the United States, of which about two hundred and 

 twenty-five species are peculiar to this country. According to 

 Kellicott, about one hundred species are found in the State of 

 Ohio, and Williamson thinks that even more are to be found in 

 Indiana. In many places dragon-flies are disappearing, owing to 

 the drainage of their breeding places. 



On account of the beauty of the adults and the interest at- 

 taching to their habits, they are becoming favorite subjects for 

 collections, and there are now a number of earnest students of 

 the Odonata in this country. The recent death of the great 

 master of dragon-fly science. Baron de Selys-Longchamps, of 

 Belgium, December ii, 1900, has called renewed attention to 

 this fascinating group. 



The nymph dragon-flies are well adapted to aquarium study. 

 They are easily collected and easily kept. The debris at the bot^ 

 tom of ponds can be brought up with a rake, and the nymphs 

 thus collected placed in a bucket and carried home to the 

 aquarium, which should be furnished with sand and aquatic 

 plants. The best time for collecting them is in the spring and 

 early summer. 



TABLE OF FAMILIES 



Wings alike, held vertically in repose; eyes constricted at 

 base, peduncled i 



Front wings dissimilar from hind wings, held horizontally in 

 repose ; eyes not peduncled 2 



368 



