AQUATIC INSECTS IX NEW YORK STATE 



221 



CaLOPTERYX 



This strongly marked genus is abundanth' represented about 

 the borders of creeks and small rivers throughout the State, 

 specially where such streams traverse rocky woods. The showy 

 imagos, with their black or smoky wings, and bodies of brilliant 

 metallic green, are very conspicuous, and well known insects. 

 They usually remain in proximity to their native streams, but 

 sometimes follow paths for a considerable distance through 

 adjacent woods. Their flight is poor and fluttering, and on 

 windy or cloudy days they keep rather closely to shelter. The 



3 Nymph of Calopteryx maculata 



nymphs rest on silt-covered vegetation or on roots swaying in 

 the current, and are rather inactive, moving but little from 

 place to place. 



The known nymphs agree in the possession of long cylindric 

 bodies, heads dorsally depressed, antennae with unusually de- 

 veloped basal segment, exceeding in length all the other seg- 

 ments put together, labium with a median cleft which divides 

 the median lobe far below the level of the bases of the lateral 

 lobes, a pair of spinules beside the cleft within, and three others 

 at the base of each lateral lobe, legs long and thin, radiately 

 arranged, gills three, variable in proportions, but always stout, 

 the lateral pair with external carina, the middle one two-edged, 

 all easily broken off, and generally wanting from specimens 

 that have received too rough treatment. 



