Suborder: Frontoventral cirri as 2 or more zig-zag files almost full length of ventrum.
Family: Frontal cirri differ in size and/or pattern from ventral ones of files; "collar" extends short distance along right edge of body; oral area not U-shaped (Illustrated Guide, 1985).
Genus: Cell body elongate with a large AZM; 2 rows of marginal cirri, 2 rows of mid-ventral cirri; no true frontal and no transverse cirri (Carey, 1992).
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U. roscoviana ?
275 x 58 μm