A new species, Botryocladia bahamense D.L. Ballantine et N.E. Aponte, from deep water in the Bahamian archipelago (tropical western Atlantic) is described. The new species is unique in having vesicles that initially are incompletely corticated with cortical cells arranged in a rosette pattern surrounding the margins of medullary cells; however, vesicles or portions of them may become entirely corticated with maturity. Algae are small, to 25 mm in height, with ovoid vesicles irregularly radially placed around the axis. Obovate gland cells are borne on medullary cells which either project into the vesicle cavity or not. The new species is monoecious and mature ostiolate cystocarps project equally inwardly and outwardly from the vesicle surface.