Two new species of Chrysymenia, C. littleriana and C. nodulosa, are described from subtidal habitats, and compared to worldwide members of their morphological form-group, and to the other species of the tropical western Atlantic. Chrysymenia nodulosa, from the southwest coast of Puerto Rico, is characterized by its terete to compressed axes, opposite or alternate pinnate branching to 2 orders, nodulose swellings on the thallus surface, and spermatangia produced in anticlinal rows. Chrysymenia litteriana, from southern Martinique, is characterized by compressed axes, opposite pinnate branching to 5 orders, a lack of nodulose swellings, and spermatangia in periclinal rows. Among the known species of Chrysymenia, C. bullosa is recognized to be a Botryocladia and a new combination is proposed. Observations suggest that the ontogeny and structure of spermatangia in species of Chrysymenia be investigated as taxonomic characters, possibly for subgeneric groupings.