CORIXsE 99 



a beetle ; they are hard and shiny, brown 

 in colour, with dark mottled markings upon 

 them. The posterior pair are transparent. 

 The abdomen is light yellow and fringed 

 with hairs, and there are transverse lines 

 on the dorsal surface of the thorax. As, 

 however, these markings on the thorax 

 and wings are hardly visible to the naked 

 eye, they give the Oorixa a generally 

 brownish and shiny appearance. Of the 

 legs, six in number, the hind pair are 

 most used in swimming. They are some- 

 what flattened at their extremities to a 

 paddle shape, and are fringed with hairs. 

 I have seen the hind legs of the Corixse 

 when the insects have been suspended 

 motionless in mid-water, standing out at 

 right angles on each side of the body ; 

 and as in the imitation I am about to 

 describe, the legs take this position when 

 the fly is at rest or sinking in the water ; 

 this explains the fact of the trout taking 

 them in the way I have mentioned 

 above. 



The Corixa sahlbergi, which is almost as 

 common as the Corixa geoffroyi, is about 

 half its size, but is otherwise very similar 



H 2 



