Prostoma simplex, Timofeeva, 1912

Kajihara, Hiroshi, 2025, A taxonomic revision of the freshwater monostiliferous hoplonemertean genus Prostoma Dugès, 1828 (Nemertea: Eumonostilifera): a radical solution or an over-lumping?, Zootaxa 5646 (4), pp. 451-500 : 488

10. Prostoma simplex

(Annex Fig. 1I)

Description. Up to 9 mm long and 0.6 mm wide. Small nemertean, relatively long, rather thick. Body anteriorly barely narrowed, posteriorly thick, ending bluntly. Body colour white, with light, yellowish tint; almost opaque, no marks. By the shape of the body, it is better to attribute it to the genus Oerstedia .

Locality. Sand with small, broken shells, 35–40 m deep (Annex Fig. 2 , XV), abundant.

Remarks. The original figure (рис. 9) shows two accessory stylet pouches, each containing three accessory stylets; now Tetrastemma simplex ( Timofeev, 1911) .

Figures

FIGURE 2. Prostoma clepsinoides Dugès, 1828 from Lake Biwa, Japan. A, Entire specimen in living state, lost after photographed. B, C, Transverse sections through proboscis anterior chamber; white arrowheads pointing to proboscis nerves. D, Sagittal section through the opening of the oesophagus–rhynchodaeum complex; black arrowheads pointing to cilia on ventral wall of oesophagus; anterior to the left. E, Magnification of D, showing sparse cilia on ventral wall of oesophagus, indicated by black arrowheads. F, Magnification of D; black arrowhead pointing to longitudinal muscle fibre along rhynchodaeum.G, Sagittal section near rhynchodaeal opening; anterior to the right. B, D, E, F, ICHUM 6272; C, ICHUM 6277; G, ICHUM 6273.