The famous nocturnal Hex hatch of the Midwest (and a few other lucky locations) stirs to the surface mythically large brown trout that only touch streamers for the rest of the year.
Arculus: An inflexed (subtly, broadly indented) point on the posterior edge of a caddisfly forewing, where vein Cu2 hooks backward to the wing edge and often fuses with the end of vein 1A.