Tail: Scarlet quill sections
Tip: Green floss tied as a butt *
Hackle: Yellow and crimson tied palmer **
Body: Yellow floss
Wing: Barred Mandarin ***
* The tip listing of green floss is shown as a butt on the painting.
** Notably, the Beatrice is the first of only a few wet flies calling for two colors of palmered hackle. It took me a long time to figure out that the best results for double palmer hackles are obtained by stripping one side (always the leading edge) and winding both stems simultaneously, by hand (no hackle pliers). This may also be done with folded hackles, but even then, both feathers need to be wound at the same time. (see my version, Beatrice, Variation III in Forgotten Flies – http://www.rareandunusual.com/beatrice%20variation%20III.html Since tying those flies in 1997-1999 my preference has changed; I now believe a folded double-hackle palmer overdresses the fly.
*** Nowadays the barred Mandarin in the wing of the Beatrice and many other flies is usually replaced with barred wood duck (see the historical information regarding wood ducks in the introduction).