28o THE DRY-FLY MAN'S HANDBOOK 



men as the brown silverhorns. Very common on the 

 Thames and its tributaries. 



Leptocerus albifrons. A chocolate-brown silver- 

 horns, with white markings on its wings. Very com- 

 mon on certain portions of the Test and other rivers. 



The Mystacides, or black silverhorns, have a spur 

 formula of o, 2, 2. 

 Mystacides. Mystacides nigra. The wings 



are black, the hind ones a trifle 

 paler than the fore-wings, and in the fore-wings a 

 metallic purple lustre may be observed. 



Mystacides azurea is distinguished from M. nigra by 

 its more slender form and narrower wings of a steel- 

 blue colour. 



Mystacides longicornis. This fly is the grouse wing 

 of the North, and the popular name exactly describes 

 the mottled brown patches on the wings. It differs 

 from the two above-named species in its general brown 

 appearance. The Mystacides are referred to in more 

 detail at page 265, under the marginal heading of 

 black silverhorns. 



HYDROPS YCHID^ 



The spur formula for both sexes is 2, 4, 4. The 



genus is peculiar in having a 



Hydropsyche. slightly elevated and blackened 



ridge winding round the an- 

 tennae in a loose spiral, described by McLachlan. 

 The species are difficult to separate and many of 

 them appear in bright sunshine. 



