Sigambra wassi Pettibone, 1966 Fig. 11

Sigambra wassi Pettibone, 1966: 186-190, figs 17,18; Wolf 1984: 29-8, fig. 29-4 a–j .

Type material.

Holotype (USNM 30988), NW Atlantic, Chesapeake Bay, off Rappahanock River (37°37.3'N, 75°59'W), 11 m, sand, Jun. 1962, M. Wass, coll., incomplete posteriorly. Paratype (USNM 30987), off Rappahanock River (37°37'N, 76°11'W), 13 m, mud, Jul. 1961, M. Wass, coll., broken and in three pieces.

Clarification.

The original illustrations and descriptions deserve some clarifications. Antennae are certainly of about the same length, but they are not tapered but digitate, and surpass the tips of palps, at least the right one (Fig. 11A). The pharynx is fully exposed, and the basal ring has about 20 irregular hemispherical lobes, but the anterior margin is eroded and damaged (Fig. 11B), such that its marginal papillae are difficult to detect; there are vague indications of the presence of approx. eight large papillae (Fig. 11C). They would include some round projections which might represent the eroded base of papillae, or that they were collapsed when the specimen was compressed into the container.

The posterior end is twisted in the paratype. It had to be pressed by a glass slide in order to have a better observation of the pygidium and anal cirri (Fig. 11D). Anal cirri are delicate, three times longer than pygidial width and tapered (Fig. 11E), not subcylindrical as originally illustrated.

Remarks.

After the study of type material, the number of marginal papillae is not defined for S. wassi Pettibone, 1966. Their number might be the same as in S. ligneroi sp. nov. described above, but better specimens are needed to clarify this. On the other hand, most diagnostic features for the species were confirmed by Wolf (1984), the fragility of anal cirri might explain why they were not observed by him.