Artacama crassa Hartman 1967

"Artacama crassa, new species

(Plate 4-9)

Records: 12:3 sta. 434 ( 1, TYPE) ; 16:28 sta. 64-63 ( 1).

Description: A complete specimen (Fig. A) is thick, tumid, meas­ures 44 mm long by 8.5 mm wide and consists of 30 setigerous segments; the long, thick proboscis is about 8.0 mm long and nearly as wide. The thorax consists of 17 and the abdomen of 13 segments. The posterior end terminates in a blunt ring with a midventral anal aperture. The char­acteristic proboscis is thick, ovoid, and has longitudinal rows of subspheri­cal papillae (Fig. C), most abundant in the distal half. Branchiae occur in three paired clusters, on three successive segments ; each cluster has 10 to 12 slender filaments ; some are short, others long, and those on successive segments are similar.

The peristomium is a large, fleshy segment with the bases of thick tentacles, some of which are still attached. Nephridia number five pairs, their external pores visible on the second branchial and the third, fourth, fifth and sixth setigerous segments.

Thoracic setae are first present from the fourth, or third branchial, segment, and uncini are first present from the fifth or following one. Uncini occur in single rows on the first six, then in double rows from setigers 7 to 17. Abdominal neuropodia have large, subcircular, folia­ceous lobes, which increase in size posteriorly ; the seventh from the last is shown in Fig. B. The uncini occur in single rows; each has a large fang surmounted by several rows of slender teeth (Figs. D, E).

Artacama crassa differs from A. proboscidea in that the proboscidial papillae are conical and fleshy ; the body is thick and tumid throughout, not tapering distally ; and the abdominal foliaceous lobes are conspicu­ously larger.

Distribution: Bransfield Strait, in 71-77 m; Antarctic Peninsula, in 47 fms."

(Hartman, 1967)