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.
Lest it be not discerned, I will state openly that the common name "howdy," which I apply to the members of this genus, is a very free trans-lation into western vernacular of the generic name.
Now, the reference to Twain could be another matter...