Orbiniella uniformis Hartman 1967

“Orbiniella uniformis, new species

Record: 16:3 sta. 6-63 (2, TYPE).

Description: The body is long, linear, slightly depressed, and uni­formly uniannulate throughout. Length is 6 mm; width 0.35 mm; and segments include two smooth buccal rings followed by 30 setigerous segments ; the body terminates in a short pygidium slightly narrower than the last segment and nearly as wide ; the anal pore is bounded by a pair of short lobes, together making up the pygidial ring.

The prostomium is a plain, semicircular lobe, broadly rounded in front, with a straight posterior margin; it lacks eyes or other surface marks. The two buccal rings are smooth, equally long, lack parapodia, and the first one forms the lower lip. Parapodia are biramous from the first; all are short, papillar, and have no accessory lobes. Setae project from the parapodia in lateral series. All setae are simple; notosetae are longest, simple, crenulated or camerated along the convex edge, as char­acteristic of the family. Neurosetae are slightly shorter than notosetae and less conspicuous, but resemble the notosetae. A thick, slightly fal­cate acicular spine is present and from segment 15 in neuropodia its shaft is thicker than that of the camerated neurosetae. Furcate setae have not been identified.

Branchiae and dorsal and ventral cirri are absent. Segments 16 through 19 contain large, perhaps mature, elongated ova; the body wall is distended in these segments.

Orbiniella uniformis differs from other species of the genus in its ex­ceedingly plain, unadorned segments; the specific name refers to this character.

Distribution: Antarctic Peninsula, in 4 fms.”

(Hartman, 1967)