H. longisacculatum (Yamaguti, 1933) n. comb.

Type host. Spotted redshank, Tringa erythropus (Pallas) (Syn. Erythroscelus erthropus Pallas) ( Charadriiformes: Scolopacidae).

Type locality. Niigata Prefecture, Japan.

Remarks. Originally described as Corpopyrum longisacculatum Yamaguti, 1933, this species was considered to be a synonym of Corpopyrum capellae (Yamaguti, 1933) (= H. capellae [Yamaguti, 1933] n. comb.) by Bashkirova (1950) and of Cyclocoelum (Haematotrephus) phaneropsolus Stossich 1902 (= Haematotrephus phaneropsolus Stossich, 1902), Cyclocoelum halli Harrah, 1922 (= Harrahium halli [Harrah, 1922]), and Cyclocoelum nittanyense Zeliff, 1946 by Dubois (1959). The pretesticular ovary in this species forms a triangle with the diagonal testes (Haematotrephinae), the genital pore is postpharyngeal and the vitelline fields are not confluent posteriorly, placing it in Haematotrephus . “Mouth with weakly developed musculature is funnelshaped”; which suggests that a rudimentary oral sucker is present, but this feature was not measured—Yamaguti (1933).