Heterolepidoderma macrops Kisielewski 1981

Heterolepidoderma macrops Kisielewski, 1981

(Figure 8)

Localities. Freshwater Sphagnum spp. rockpool, Hållö (N 58º 20’ 00’’; E 11º 12’ 50’’); A small pond close to lake Torneträsk at Abisko Scientific Research Station, Abisko, Lapland (N 68º 21’ 19’’; E 18º 49’ 21’’); Among moss, Björkliden, Lapland (N 68º 24’ 25’’; E 18º 41’ 36’’).

Material. 5 specimens. TL, 143–150 µm; FL, 17 µm; AL, 10 µm; PhL, 33–37 µm; MD, 4 µm; DC, 27–33; DR, 30; TS, 5 x 1–2 µm; VTS, 4.5 x 2.5 µm.

Mid sized species with rounded to five-lobed head, characterized by two large ocellar granules. Two pairs of dorsal sensory bristles, posterior pair anchored by double keeled scales. Dorsal body surface covered by elongated elliptical keeled scales without spines. Scales are ordered parallel to the body outline except for the median column which is more or less straight. Interciliary area naked except for two keeled ventral terminal scales. Ventral ciliation in two longitudinal bands that are further divided on the head, but do not merge. Pharynx with weak swellings at both ends. The number of dorsal columns and the length of Swedish specimens are close to or just above the upper limit of literature data.

Previously recorded from France (Kisielewski 1998), Germany (Schwank 1990), Poland (Kisielewski 1998), Russia (Tretjakova 1989) and perhaps United States and Japan (Schwank 1990).