Eleven species of Bugula are known to occur in British waters, including three that have not previously been described. The characters of greatest value for separating these species are reviewed. Full descriptions are given of B. neritina, B. plumosa, B. purpurotincta, B. stolonifera sp. nov., B. avicularia, B. turbinata, B. flabellata, B. fulva sp. nov., B. calathus, B. aquilirostris sp. nov. and B. simplex. The account includes notes on habitat, breeding season and geographical distribution; and a key is provided to facilitate identification.

B. ditrupae, from Madeira, is redescribed and compared with B. fulva and B. aquilirostris, as the three species have hitherto been confused. Synonomies of each are given.

The B. simplex of most authors is not that of Hincks, but another species: possibly of form konwn as B. plumosa var. aperta. B. simplex is the B. flabellata of most American authors, and the B. sabatieri of those writing on Mediterranean Polyzoa. Synonomies of B. simplex and B. flabellata are given.

A full description of B. turrita and summary descriptions of B. californica, B. pedata and B. geermanae are given, and these species are compared with B. stolonifera. The characters of B. spicata are mentioned as it also has been confused with some of the above species.