THE INSECTS. 



333 



the rest of the nervation concolorous with the wing mem- 

 brane or yellowish-green. 



Female Imago. Very like the male, but with dorsal 



EPHEMERA DANICA. 

 i, Male Imago. 2, Female Imago. 



markings of the pale cebreaceous abdomen better defined ; 

 fore-legs piceous, hind-legs olive-grey ; wing membrane 

 colourless, hence the narrow grey 

 bordering of the cross veinlets is 

 better shown than in the male ; spots 

 grey ; setae brown-black. 



Pictet, 1843. EPHEMERA VULGATA. 

 Male Imago. Head and throat 

 peach - brown ; mouth and sides of 

 throat yellow; abdomen yellow, a long 

 black mark on the edge of each 

 segment ; two of the same form above 

 and two below the latter are not seen 

 on the first segments, and become 

 larger in the lower divisions, covering 

 them for the most part ; fore-legs 

 black, hind-legs greyish ; setae dark- 

 brown, ribbed with black ; anterior 

 wings tinted with brown, nervures EPHEMERA VULGATA. 

 dark brown with numerous trans- imago, male. 



verse veinlets ; spots on wing vary in individuals, gene- 



