New Zealand Exclusive Economic Zone, Portuguese Exclusive Economic Zone, Spanish Exclusive Economic Zone

Type locality: Not specified, England.

Reported for Europe, America, New Zealand.

Body fusiform, elongate, slender; hyaline. Head offset by distinct neck-fold, completely retractable. Tail small, prominent. Foot very long, ~ 1/3 total length, very motile, 3 pseudosegments: basal short, ± conical, median long, ± cylindrical, terminal very short, usually partially retracted in median. Toes ± lanceolate, abruptly ending in tubular points, bases partially fused, often slightly recurved dorsally. Corona slightly oblique, 2 lateral ciliary tufts. Brain large, saccate. Two frontal eyespots, x-like set together, occasionally fused. Stomach and intestine separated by constriction. Gastric glands oval. Pedal glands very long, extending into trunk. Subitaneous egg elongate oval, attached to substrate by short tag.

Trophi malleate, symn1etrical; basal part of rami with rounded a1ulae and large, plate-shaped basal apophyses with comb of ± 12 teeth; anterior part thin, Y-shaped. Fulcrum short, posterior end strongly expanded in ventral view; in lateral view ± wedge-shaped, posterior end slightly expanded. Unci symmetrical, 3-4 rounded teeth, gradually decreasing in size; principal teeth each with prominence on ventral margin; under side with skleropili on anterior margin of uncinal plates. Manubria club-shaped, wide, posterior half curved ventrally, posterior and anterior cavities in upper half. A thin ± triangular plate between malleus and incus. Occasionally 2 thin, kinked, pleural rods.

Length 265-500 µm, toe 27-39 µm; trophi 22-29 µm: ramus 14-18 µm, fulcrum 6 µm, uncus 10-12 µm, manubrium 23-26 µm; subitaneous egg 88-116x50-62 µm.

Marine and brackish water.

Food: diatoms, detritus, bacteria, dinoflagellates.

In mountain springs and littoral of alkaline stagnant and running fresh waters, also among algae in littoral of brackish and marine waters.