S. paradoxum (Marcó del Pont, 1926) n. comb.

Type host. Common gallinule, Gallinula galeata (Lichtenstein) ( Gruiformes: Rallidae).

Type locality. Buenos Aires, Argentina—Thatcher (1993).

Remarks. This species was considered to be a synonym of Cyclocoelum mutabile (Zeder, 1800) by Dubois (1959). Yamaguti (1971) gave an egg length of 60 for this species; however, it is 160 in the original description by Marcó del Pont (1926). The original description provides only measurements of a body length, an egg length and an egg width; however, Fig.1 of the original description does not show the cirrus sac. The presence of a rudimentary oral sucker is indicated in the description (“Pharynx immediately ahead of the union of the two intestinal branches, leaving only a tiny esophagus and something behind the mouth, which is infundibular.”) and Fig. 1 of the original description by Marcó del Pont (1926).