Hydrobiidae (Gastropoda, Neotaenioglossa, Rissooidea) da planície costeira do Rio Grande do Sul, Brasil

REDESCRIPTION OF POTAMOLITHUS CATHARINAE BASED ON TOPOTYPES (GASTROPODA, HYDROBIIDAE), HERCÍLIO RIVER, SANTA CATARINA, BRAZIL. Potamolithus catharinae Pilsbry, 1911 is characterized on specimens from Hercílio river, State of Santa Catarina, Brazil, type-locality. Conchology, conchometry, soft-part morphology including head and food complex, pallial structures, radula and some aspects of the female and male reproductive systems are provided.