I'm no expert in this area but I should mention the PLECTRUM banjo. It descends from the five string banjo being basically a five string without the fifth string. It differs from the tenor banjo in having a longer neck (same as the five string) and being tuned usually in old time 'C" tuning: c-g-b-d. It seems to have its origins in some type of minstrel tradition. It's virtuoso was Eddie Peabody who was a very old man in the late fifties. He played old chestnuts. I've seen plectrum banjos hanging in music stores. I know where there's a Lyon and Healy (pre-war) right now. That's about all I know of these.