Silk: Pearsall's Gossamer #10 Ash
Hackle: Undercover for Woodcock
Rib: Tying silk twisted with one or two Heron herl fibers.
One fiber twisted in rib

Two fibers twisted in rib

I've been playing with historic North Country Flies this week. This is from B. Bradley's list, 1870. It's not often that I geek out over historic patterns, unless they have a direct fishable application on streams I fish, and many do. This could represent any number of things, but I don't know of anything specific. Does anyone know what it was supposed to represent in the UK?
w