A Comparative Study of the British Species of Nucula and Nuculana

The survey of the sublittoral fauna of the Clyde Sea Area from 1949 onwards has shown that five species of the Protobranchiata are abundant throughout this region on a variety of substrata. Pelseneer (1891, 1899, 1911), Heath (1937), and Yonge (1939) have contributed much to the knowledge of the group as a whole, but little comparative work has been done at species level. Verrill & Bush (1897, 1898) studied the shell characters of the American Atlantic species. Moore (193Ia, b) worked on the faecal pellets of the British Nuculidae and attempted to distinguish the species by this means~ while Winckworth (1930,1931), mainly in the light of the latter work, attempted to clarify the nomenclature of these species. Winckworth (1932) lists six British species of the family Nuculidae: Nucula sulcata Bronn, N. nudeus (Linne), N. hanleyi Winckworth, N. turgida Leckenby & Marshall, N. moorei Winck'Worth and N. tenuis (Montagu); and four species of the family Nuculanidae: Nuculana minuta (Muller), Yoldiella lucida (Loven), Y. tomlini Winckworth !lD.dPhaseolus pusillus (Jeffreys). All species of Nucula, except N. hanleyi, were taken from the Clyde Sea Area, although the latter species is included in the Clyde fauna list (Scott Elliot, Laurie & Murdoch, 1901). Only Nuculana minuta of the Nuculanidae has been taken on the present survey. Yoldiella tomlini is included in the 19°1 list but is noted as being' insufficiently attested'. Nucula hanleyi was obtained from the Marine Station, Port Erin, but Yoldiella and Phaseolus were unobtainable.