£1 



Genus XLVII. EPHEMERA. 



GENERIC CHARACTER. 



Antenna thin, setaceous, and shorter than the 

 head. Mouth without mandibles. Palpi 

 four, very short, nearly equal and filiform. 

 Stemmata two, large, and situated above the 

 eyes. Wings erect, the hind ones very small. 

 7 Tail terminated by two or three setaceous 

 filaments. 



General Observations. 



Of the two sections, into which Linnaeus has 

 divided this genus, the insects of the first have 

 two, and of the second three bristles in the 

 tail. 



The Ephemera derives its name from its short 

 and transient existence in its perfect state. Some 

 of the species die the same hour they are born ; 

 others never see the sun, they burst through 

 their filmy covering at the close of day, and die 

 before the dawn. The term Ephemera is not 

 strictly correct; for the existence of certain spe- 

 cies is prolonged for two or three days; conse- 



