A NEW SPECIES OF THE GENUS STEPHANOPRORA ODHNER, 1902 (DIGENEA, ECHINOSTOMATIDAE) FROM ARGENTINA

Stephanoprora podicipei sp. n. parasite of great grebe Podiceps major Boddaert, 1785 (Aves, Podicipedidae) from Mar Chiquita coastal lagoon (Buenos Aires, Argentina) is described and illustrated. The new specie s presents common features with S. conciliata Dietz, 1909; S. manei Ho lcman-Spector et Olague, 1986; S. dogieli Holcman-Spector et Olague, 1 989 and S. uruguayense Holcman-Spector et Olague, 1989. S. podicipei s p. n. can be clearly distinguished from these species, principally, by the smaller size of its body, peristomic disk, testes, ovary and by i ts shorter oesophagus and uterus. S. podicipei also differs from S. ar gentiniensis Sutton et al., 1982, the other species of this genus para sitizing Podiceps major in Argentina, in the number of spines of the p eristomic disk (22 vs. 20), in its smaller body, peristomic disk and t estes; in its larger acetabulum and eggs, in the shape of the testes a nd in its vitellaria extending to the middle of the anterior testis.