The Hendrickson was named for Albert Everett Hendrickson of Scarsdale, New York, an angler and friend of Theodore Gordon. The Hendrickson (Ephemerella) is one of the most important mayfly families and their hatches on many rivers are legendary. This Hendrickson bead head nymph version is a very lifelike fly pattern and imitates the early stages of emergence as the fly moves toward the surface. Color: Natural. Size: 14.