You might discover the precise distant relationship in his self-published THE CLEMENS FAMILY CHRONOLOGY 1610-1912 (1914). I have the original pamphlet, which is scarce and too fragile to copy (or I'd happily do so for you), but photocopy editions and CDs are available online at the usual book sites. You'd probably want to double-check anything claimed in that booklet with records available at ancestry.com. Clemens also published a second work on Twain's geneaology in a magazine, BIBLIO, volume II:1-12 (July 1922 --June 1923). Twain called Will Clemens a "troublesome cuss" because of Will's other publications exploiting Twain, which are well-known. Kevin Mac Donnell Austin TX