AQUATIC INSECTS IX THE ADIRONDACKS 407 



formation was certainly only opening. I collected all that appeared after 

 that daily till the end of June, at which time all the species for which I 

 thought such counting practicable had ceased transforming for the year- 

 The results of the count are as follows. 



82Gomphus exilis Selys 



20 Gomphus brevis Selys 



18 Gomphus spicatus Selys 



24 Ophiogomphus aspersus Morse 



II Hagenius brevistylus Selys 

 7 Cordulegaster maculatus Selys 

 I Didymops transversa Say. 

 I Tetragoneuria semiaqua Burnt. 

 6 Basiaeschna Janata Say 



Intermingled with these were the cast skins of a number of species 

 whose period of transformation was not finished, perhaps, by the end of 

 the month of June; viz Galop teryx maculata Beauv. (12), Argia 

 violacea Hagen (20), Enallagma sp.? (5), Boyeria vinosa 

 Say (3), and Aeschna constricta Say (2). 



It is difficult to conceive how so many of the large rapacious Gomphine 

 nymphs can get a living in so small space. I do not believe that, judging 

 by repeated collecting, they were more abundant here than in other 

 basins along the creek. I collected in this same place with a sieve net 

 after this count was ended the nymphs of the next season's brood, and 

 obtained in 15 minutes' use of the net 22 Cordulegaster macu- 

 latus, 2 Hagenius brevistylus, 40 Gomphus and 

 Ophiogomphus, 8 Calopteryx maculata and 4 Didy- 

 mops transversa. 



The life of the rapids. At the railroad Little Clear creek pours out 

 of the culvert and tumbles over a little bed of stones. This is the only 

 rapids within easy reach from the hatchery. There was no time for a 

 quantitative study of its life, but we studied it as carefully as time would 

 permit. 



The most abundant and important animal in the rapids is the black 

 fly, Simulium venustum Say. With the exception of a few Chiro- 

 nomidae which live in the " skin algae ", covering the broader surfaces 

 over which the water glides, all the life of the rapids seems to center in 

 the Simulium colonies. These are very extensive indeed, masses of the 

 swaying, dark greenish larvae, or of the yellowish pupae covering the 

 stones over considerable areas. 



