Caloglossa leprieurii (Montagne) J. Agardh was first described from a mangrove area in French Guiana. It is now placed in the red algal order Ceramiales, family Delesseriaceae (King and Puttock 1994). It is one of six genera in this family that have been reported from inland waters in North America (Sheath et al. 1993). This is its first freshwater report (north of Puerto Rico) for the United States.