344 THE RIVER-SIDE NATURALIST. 



olives, quill-gnats, &c., in the genera, Baetis, Cloeon, and 

 Potomanthus. 



It should be borne in mind that the different species 

 of insects of the family Ephemeridce we see as they emerge 

 on the surface of, or float down, the water are for the 

 most part in their sub-imago state. In their perfect or 

 imago state they are hovering higher in the air (in the 

 shape of various spinners) for the purpose of continuing 

 their species ; the female descending again from time to 

 time to deposit her eggs ; the male only occasionally, 

 in his perfect state, being found on the surface. 



The Turkey Brown of Ronalds, one of this family, with 

 three setce, is, we believe, the sub-imago of Ephemera sub- 

 marginata (?) of Stephens ; Potomanthus geerii (?) of Pictet ; 

 Leptophlebia submarginata of Eaton. 1 



The July Dun of Ronalds, another of this family, 

 with three sefce, is the sub-imago of Ephemera marginata 

 (Stephens) ; Potomanthus marginatus of Pictet. 



The Hare's Ear is the sub-imago of Baetis bioculata ; 

 the perfect insect being a spinner somewhat similar to 

 the Jenny Spinner, B. nyen. 



The March Brown or Dun Drake is the sub-imago 

 of Baetis fluminum (Pictet),. or Baetis venosa (Pictet and 

 Stephens). The male imago is one of the early Red 

 Spinners. In the "Scientific Angler" (p. 123, third 

 edition) it is stated that " in May the March Brown is 

 recognised as the Turkey Brown, light and dark, in 

 accordance with the weather;" but the Turkey Brown has 

 three setce, the March Brown only two. 



The various so-called Olive Duns may be classed chiefly 

 in the genus Baetis. Some have the wings much reticu- 

 lated, in others the cross reticulations are very faint ; 

 some also have the turbinated eyes separated, others with 

 them divided by a distinct line. There are a great many 

 shades of Olives. Baetis lateralis, the Olive Dun or Cock- 

 tail, is a good example of the reticulated wings. 



The Pale Evening Dun of Ronalds, so prevalent in the 



1 Mr. Eaton, in Part V. of his monograph, published since, gives 

 Ecdyurus insignis as the Turkey Brown of Ronalds. 



