HOW TO KNOW THE IMMATURE INSECTS 



10b. Claws of the middle and hind legs shorter than the tibiae 11 



11a. Lateral caudal filaments with very short hairs, or with longer 



hairs fringed on both sides. 



Fig. 141 Family LEPTOPHLEBIIDAE 



The naiads are elongated with three 

 equal caudal filaments as long as the 

 body and with long slender leaf-like 

 or string-like gills. 



Fig. 141. Blasturus cupidus Say 



lib. Lateral caudal filaments with long hairs on the inner side only.. 12 



12a. Latero-caudal margin of the abdominal segments with tooth-like 



projections. Fig. 142 Family SIPHLONURIDAE 



The naiads live in rapidly running 

 water and sometimes occur in cataracts 

 and waterfalls. They have small head 

 and slender legs. 



Fig. 142. Siphlonurus olterna- 



tus Say. 



12b. Latero-caudal margin of the abdominal segments without tooth- 

 like projection. Fig. 143 Family BAETIDAE 



The naiads are found in waterfalls, cata- 

 racts, slow currents and open waters. They 

 may be also found among aquatic plants in 

 still pools. The family is large and widely 

 scattered. 



Fig. 143. Gollihaetis flue- 



tuons (Walsh). 



66 



