A new species, Lima ( Acesta) bullisi, is described from 300 and 600 fathoms off Mobile Bay, Alabama. This represents the first reported occurrence of the subgenus Acesta in the western Atlantic and contiguous basins. A catalogue of the described Tertiary and Recent species of Acesta lists 13 known Recent species [L, (A.) butonensis Bartsch is considered to be a synonym of celebensis Bartsch}, and 31 species and varieties from the Tertiary deposits of North America, Asia, New Zealand, and Europe. A new subgenus, Plicacesta, is proposed for the plicately ribbed Lima smithi Sowerby of Japan, and three Asiatic Tertiary species are also referred to it.
