Gol, Oken, 1815

Acd, 2000, Sipuncula from Hainan Island (China), Journal of Natural History 34, pp. 2187-2207 : 2192

Subgenus Gol ®ngia ( Gol ®ngia) Lankester, 1885 Gol ®ngia ( Gol ®ngia) elongata (Keferstein, 1862)

Material. Qukou, 13 March 1992, one specimen.

Description. Trunk 17 mm long and 1.2 mm wide. Introvert shorter than the trunk, 3 mm long. The skin is smooth, translucent and of a whitish colour. Small, scattered digitiform papillae of about 10 m m in diameter. Hooks in a few rings, 50±70 m m in height (®gure 2b, c). Four retractor muscles are inserted in the anterior 20% of the trunk.

Discussion. The presence of hooks in rings is especially diagnostic for the species, although in the specimen studied the rings were observed with some di culty. The character of the retractors concerning the insertion point in the body wall, and the small ratio introvert/trunk length are also important. The presence of papillae had not been previously described for the species, skin bodies (Saiz Salinas, 1993) had been reported instead.

The geographical distribution of the species is mainly Atlantic, but it has also been found in the southern and eastern seas of China (Leroy, 1936; Murina, 1964; Li et al., 1992b) in depths of 90±590 m, and in Vietnam (Murina, 1989) in the sublittoral zone. However, this represents the ®rst record for Hainan Island. It has been found in sandy and muddy bottoms, rock crevices and other hard substrata.