
The lower sandstone A appears equivalent to the blue standstone of Nulato, the upper beds across the harbor to the brown do of Nulato, the porphyrite do to that of the  Sopka - at Koyukuk. 
The lower sdst. here (as there) exhibits obscure vegetable remains and its upper beds (as at Ulukuk) leaves &c but of different species from those of the Portage. The upper layer with crepidulas corresponds to those containing oysters & mybili of Nulato - though this is not represented on the island but across the Harbor.
The upper beds (B) here are simple continuations of the lower (A) which passes insensibly into them and they are succeeded by the lignite bearing series &