Also known as Old Man Marsh, is the grandson of Obed Marsh and the owner of the Marsh refinery at the time of The Shadow Over Innsmouth. Barnabas' father was Onesiphorus Marsh, Obed's son by his first, fully human wife; though his mother, who was never seen in public, was apparently a deep one. Zadok Allen says of him: "Right naow Barnabas is abaout changed. Can't shet his eyes no more, an' is all aout o' shape. They say he still wears clothes, but he'll take to the water soon."
