O. magalhaesi Travassos, 1921

Type host. Muscovy duck, Cairina moschata (Linnaeus) ( Anseriformes: Anatidae).

Type locality. Brazil.

Previously proposed synonym. Ophthalmophagus nascicola Witenberg, 1923 — Joyeux & Baer (1927).

Remarks. This species was considered to be a synonym of O. singularis (Stossich, 1902) by Dubois (1959). It is similar to O. bucephali Dronen & Blend, 2007 and O. plectopteri Dubois, 1930 by having the posttesticular ovary close to, or contiguous with the posterior testis, but it differs from both these species by having a much larger egg size (219 x 105). No oral or ventral sucker described—Travassos (1921); Dollfus (1948); Bashkirova (1950).