CADDIS-FLIES 279 



Odontocerum albicorne, spur formula 2, 4, 4. A 

 very handsome grey sedge with dark markings. 



When at rest the long white 

 Odontocerum antennse are pressed closely 



albicorne. together and project straight 



in front, continuing the line of 

 the body. The generic name is derived from the 

 Greek d(5ow, a tooth ; and Kspala, a horn ; and the specific 

 name emphasizes the white colour of the antennae, 

 and is taken from the Latin albus, white; and cornus, 

 a horn. The Greek generic derivation describes the 

 curious toothed appearance of the antennae, which 

 can be observed under a glass of quite low magnifica- 

 tion. There appears to be only one species in the 

 whole genus. 



The spur formula for both sexes and all species of 



the genus Leptocerus is 2, 2, 2. 



Leptocerus. Leptocerus nigro-nervosus. A 



large, strong-flying sedge with 

 long dark antennae. As may be inferred from the 

 Latin derivation of the specific name, the wings are 

 very strongly marked with heavy black neuration. 

 This fly is fairly general, and has been observed in 

 large quantities along the shores of Lough Arrow. 



Leptocerus aterrimus. A very common form, similar 

 to the black silverhorns of the angler. It is dis- 

 tinguished from it by the two spurs on the fore-legs, 

 the true black silverhorns having none. 



Leptocerus cinereus. A very common and plentiful 

 species, and is probably the insect referred to by fisher- 



