A Fast-Sinking Stonefly Nymph With an Anatomically Molded Tungsten Head for Unmatched Realism. Everything You Need To Tie 8 Stonefly Prince Nymphs. A next-generation stonefly pattern inspired by the classic Prince Nymph and enhanced with an Evolution Stonefly beadhead. This Fly Tying Kit contains everything you need to tie 8 Stonefly Prince Nymphs, including step-by-step tying instructions, to make it easy for you to get your hands on the various needed fly tying materials all in one place.