O. charadrii Yamaguti, 1934

Type host. White-faced plover, Charadrius alexandriunus dealbatus Swinhoe ( Charadriiformes: Charadriidae). Type locality. Sizuoka Prefecture, Japan.

Remarks. This species was considered to be a synonym of Ophthalmophagus singularis (Stossich, 1902) by Dubois (1959). No oral or ventral sucker present—Yamaguti (1934).