I have already posted this on a UK BB, I thought it might also be of interest here.
Here are two versions of a fly from Turton which I later discovered was an imitation of the Alder Fly without the wings on the version by Kingsley and is meant to be a wet fly. I read Dave Hughes book 'Wet Flies' many years ago, and remembered his comments about the behaviour of the natural insect on the water. First thing is, that it is a non-floater, it lands on the water with a distict plop, sinking almost immediately, second the fish take it sub-surface. There is only one pattern for the Alder (Kingsley), well there are but they are all very much the same, and they seem to be floaters. In Roger Fogg's book 'Manual of North Country Trout Flies' he mentions how it seems to have gone out of favour, this is quite common with a lot of North Country patterns which are excellent trout catchers. I have up-dated it a bit, a modern hook, and CdL hen hackle. In the second pattern I have added a wire under-body to give it more plop and work deeper in the water column. I hope it meets with your approval after 177 years.

Modern Orl Fly #1.
Hook:- #10 Grip Hook ( Fogg said 10 - 12).
Silk:- Chinese Red YLI.
Body:- Three strands peacock herl.
Hackle:- CdL hen, speckled brown.

Basically the same except
an under-body of Red wire, Uniwire small.