Prometor Fisher 1948

Prometor sp.

(Fig. 4A)

MATERIAL EXAMINED. — Porcupine Abyssal Plain, BEN- GAL 2, Discovery 226, stn 13078#11, 48°53.19’N, 16°35.98’W, 4844 m, 1.IV.1997, 1 ♀.

DESCRIPTION

Colour of proboscis is cream, trunk is pink in preserved specimen. Proboscis is truncate, 0.5 mm long, slightly flattened distally with straight anterior margin (Fig. 4A). Lateral margins of proboscis fuse at base forming cup leading to mouth; cup with small lobes around margin (Fig. 4A). Trunk is cylindrical, 13 mm in length, covered with conspicuous, raised papillae (Fig. 4A). Body wall thick and opaque, damaged at posterior end of trunk. Ventral setae one pair, golden-yellow in colour. Each seta consists of cylindrical shaft with flattened and slightly curved terminal blade (Fig. 4A).

Except for anal vesicles,rest of internal organs missing. Anal vesicles are two slender tubes opening into cloacal bulb and bearing long stalked funnels

REMARKS

The present specimen has been assigned to the genus Prometor on account of the presence of a cup at the base of the proboscis that leads to the mouth; a truncated proboscis; unbranched anal vesicles and two well developed ventral setae. Unfortunately the gonoducts and other internal organs were missing in the specimen. According to the descriptions provided by Fisher (1948), Zenkevitch (1957), Hartman & Barnard (1960) and Saiz-Salinas et al. (2000) there are two gonoducts that open to the exterior by means of a common genital pore.

Four species are currently known in the genus Prometor. The specimen on hand differs from all the species in the genus in possessing a cup with lobes around the margin. In view of this important difference it seems very likely that the present specimen represents an undescribed species. However, it is considered undesirable to erect a new species on the basis of a single incomplete specimen. Additional material in the future will help resolve its taxonomic position.