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).

100 μm 200 μm 300 μm; x 200 : 50 μm 100 μm 150 μm; x 400