This is a great smallie fly. Why I do not know but they’ll come up from the bottom and hit it just as Murray describes. He called it Drakes Slidder as he gave credit to Drake..... it is a slider. As mentioned above,I first ran across it in harry Murray’s first Fly Fishing forSmallie Book(1989) he had a drawing off it that looked spot on to your tie. i also recall a post and instructions for a man who knew E Drake. The bead was to form the head and not for any other purpose. But who cares.... it may offer different and attractive options in various materials and wgts. The instructions called for red thread behind the bead and used a washer or die to hold the hair in place. I use yellow hair and feathers. Have never used a washer to hold the hair in place but a fussy tier may find that useful. Here is a bit from the book
http://books.google.com/books?id=Hp7z6byr8...p;q&f=false