The occurrence of Neogoniolithon fosliei (Heydrich) Setchell et Mason in the Mexican Carribean and the relationship of this species to N. solubile (Foslie et Howe) Setchell et Mason (Corallinales, Rhodophyta)

We report Neogoniolithon fosliei from the Mexican Caribbean, after comparing its type from the Red Sea and lectotype from Puerto Rico with specimens of N. solubile from Mexico. We propose that these two taxa are conspecific, since they display a similar morphology on the following characters: (1) nongeniculate thallus with a flattened dorsal surface lacking protuberances, (2) ventral region (medulla) arranged in a coaxial manner and occupying 50-75% of the thallus thickness, (3) monomerous construction, (4) cells of adjacent filaments connected by lateral fusions, (5) trichocytes similar in size and occurring singly and in horizontal or vertical rows, (6) epithallium composed of a single layer of cells, and (7) similar in size epithallial, cortical and medullar cells. Neogoniolithon solubile is recognized as a junior synonym of N. fosliei and we refer our Caribbean material to the latter species that has nomenclatural priority.