MAYFLIES, DUNS AND SPINNERS 247 



The pale watery spinners can be identified by the 



hind wings, and Plate XXI 

 Pale watery spinners, shows a male spinner with the 



head in profile on a larger 

 scale to show the turbinate eyes and a ventral view 

 of the hinder end of the body, on the same scale to 

 show the abdominal forceps of the male. The tur- 

 binate eyes of the male pale watery spinner vary con- 

 siderably in the different genera and species generally 

 designated by this name. Eaton gives them in de- 

 scribing B. binoculatus, B. scambus, C. luteolum and 

 C. pennulatwn, respectively, as lemon or bright yellow, 

 clove or warm sepia brown, bright light red, and light 

 cadmium orange. The patterns of the male and 

 female pale watery spinners are Nos. 16 and 17 

 respectively. 



Under the fisherman's name of iron-blue two species 



of the genus Baetis are in- 

 Iron-blue duns. eluded — B. pumilus and B. 



niger ; they are both fairly 

 plentiful, and it is not easy even for experts to dis- 

 tinguish between them. ^^^ 

 Plate XXII shows the 

 female, and Nos. 18 and 

 19 in the new set of pat- 

 terns are imitations of the 

 two sexes. Fig. 47 shows ^ 3° 

 the hind wing, and the student should note that it 

 differs from that of the other duns in the shape of the 

 intermediate nervure, which is forked. The smoky 



