28 



THE OLIVE DUNS 



up to the surface of the sand and grit which 

 covered the bottom, in order to slough its 

 skin, to keep pace with growth, and then every 

 living thing in the aquarium would set upon it, 

 and the unfortunate insect would be devoured 

 piecemeal. I did not succeed in rearing a single 

 specimen to maturity, as the nymph is quite 

 helpless to defend itself. When disturbed it 

 feigns death, and will remain motionless for as 

 long a space as a quarter of an hour. Then 

 when it thinks that the danger is past, it 

 burrows into the soil with incredible rapidity 

 by means of its powerful forelegs, median legs, 

 and wedge-like head. It swims through the 

 water with an undulating movement of the 

 body. 



spent gnat. Spent gnat is a term applied by fishermen 

 to the female imagines or spinners of any 

 Ephemera after the eggs have been voided and 

 the insect is floating down the stream " spent " 

 from the labours of egg-laying, and in a dead 

 or dying condition. 



Olive dun 

 and olive 

 spinner. 



Family . 

 Genus 



Species 



. EPHEMERIDJE 

 . Baetis 



Ivernus 

 rhodani 

 atrebatinus 

 tenax 

 buceratus 



PLATE II 



Fishermen in practice apply the collective 

 names olive dun and olive spinner to various 



