AQUATIC INSECTS 



live for several days in aquaria. If those with black wing- 

 pads are captured they are almost sure to emerge within 



Fig. 158. — Nymph of Callibcetis among water 

 weeds. 



a few hours into subimagos whose spotted wings are margined 



with delicate hairs (PL XI, i). Length, fullgrown nymph, 



t 



half an inch. 



Occurrence. — Generally distributed through North America. 



Fig. 159. — Nymph of Chirotenetes. 



"White-gloved howdy," Chirotenetes. — The front legs of 

 Chirotenetes are fringed with long hairs. In addition to its 

 abdominal gills it has tufts of gills at the bases of its maxillae 

 and front legs (Fig. 159). This n3"mph lives in the tumbling 

 waters of stony creeks, among which it leaps and dashes with 

 amazing agility. There it braces itself, tail down and head 

 up, and holds its front legs outward to catch its food from the 

 current (Fig. 24). 



209 



