Siphonostoma buskii McIntosh 1869:420, Pl. 15, Fig. 13a, Pl. 16, Fig. 4.
Flabelligera buskii: McIntosh 1908:533 (n. comb.); 1915:114-115, Pl. 96, Fig. 11, Pl. 102, Figs. 3-3b, Pl. 104, Figs. 8-8b.
Material examined. None available.
Diagnosis. Tunic transparent. Body brick-red. Neurohooks often in pairs, handle articles long; crests very long, width:length ratio 1:9.
Remarks. Flabelligera buski (McIntosh, 1869), a rather poorly described species, resembles F. bophortica Annenkova-Chlopina, 1924 because both have neurohooks with long crests. They differ because in F. buski neuropodia have two neurohooks per ramus and their crests are very long (width:length ratio 1:9), whereas in F. bophortica most neuropodia have single neurohooks and the crests are shorter (width:length ratio 1:6(7)). On the other hand, according to Newbigin (1900:194), juveniles of F. diplochaitus have two hooks per rami, and since their hooks have typically long crests, F. buski might be more closely allied to this species (Haase 1915:174). This confusion might be resolved with more specimens of F.buski, especially adult ones, which should have fully developed neurochaetal numbers.
The species has been regarded as juvenile F. affinis; even McIntosh repeatedly indicated this resemblance. However, because there are two hooks per rami and that the crests are unusually long, this might be a different species. However, because there is no material available, the final decision about its specific status must be postponed. Until then, the species might be regarded as species inquerenda.
Distribution: Off Loch Maddy, Northwestern Scotland, subtidal.