Cyclocoelum vicarium Arnsdorff 1908, n. comb.

S. vicarium (Arnsdorff, 1908) n. comb.

Type host. Purple sandpiper, Calidris maritima Brünnich (Syn. Arquatella maritime [Gmelin]) (Charadriiformes: Scolopacidae).

Type locality. Labrador, Canada.

Additional hosts. Eurasian curlew, Numenius arquata (Linnaeus) and dunlin, Calidris alpina (Linnaeus) (Syn. Tringa alpina Linnaeus) (Charadriiformes: Scolopacidae)— Yamaguti (1971); common greenshank, Tringa nebularia (Gunnerus) (Charadriiformes: Scolopacidae)— Bourgat et al. (1999).

Additional localities. Europe, specific locality unknown—Yamaguti (1971); Togolese Republic (Togo), Africa—Bourgat et al. (1999).

Previously proposed synonym. Cyclocoelum mehrii Khan, 1935 (= Selfcoelum mehrii [Khan, 1935] n. comb.)— Bashkirova (1950); Dubois (1959).

Remarks. This species was originally described as Monostomum vicarium Arnsdorff, 1908. It was redescribed as Cyclocoelum vicarium (Arnsdorff, 1908) by Harrah (1922). It was considered a synonym of Cyclocoelum ovopunctatum Stossich, 1902 (= Selfcoelum ovopunctatum [Stossich, 1902] n. comb.) by Bashkirova (1950) and Dubois (1959), and of Cyclocoelum obscurum (Leidy, 1887) by Joyeux & Baer (1927). The original description of this species by Arnsdorff (1908) apparently was based on two separate species representing different genera in two separate subfamilies. Figure 1 of the original description likely represents Selfcoelum vicarium n. comb. (Syn. Monostomum vicarium) because it has an intertesticular ovary forming a triangle with the testes (Cyclocoelinae), a genital pore that is postpharyngeal and the vitelline fields are not confluent posteriorly (= Selfcoelum). The second possible species, as shown in Fig. 2, appears to have a pretesticular ovary forming a triangle with the testes (Haematotrephinae), a genital pore that is postpharyngeal, vitelline fields that are not confluent posteriorly and the testes are oblique, and it would likely be assigned to Haematotrephus. However, with the lack of information concerning this second species, we have not distinguished it as a distinct species and have not included it in our key to the species of Haematotrephus. No oral or ventral sucker described—Arnsdorff (1908); Kossack (1911) and Bashkirova (1950).