Abstract
A new species of Rhinebothrium (Tetraphyllidea: Phyllobothriidae) is described from the spiral valve of three round stingrays, Urolophus halleri Cooper, collected in Anaheim Bay, Seal Beach, California. Redescriptions of R. urobatidium (Young, 1955) n. comb., R. bilobatum (Young, 1955) n. comb, and Caulobothrium multorchidum (Young, 1954) n. comb, are made from material available in the USNM Helminthological Collection and new material from the type host. The validity of generic characteristics is discussed and generic evaluations of Rhinebothrium Linton, 1890, Caulobothrium Baer, 1948, and Rhabdotobothrium Euzet, 1953, are emended.