Records in the boreo-arctic region
North-eastern Kara Sea: Off Sewernaja Semlja (Gorbunov, 1946: p. 37).
South-western Barents Sea: Kola Fjord (Breitfuss, 1912: p. 62, as Cydonium mülleri; also referred to by Hentschel, 1929: p. 920, as Geodia mülleri).
Norway: Off Vadsø, Varanger Fjord (Burton, 1930: p. 490, G. mülleri); Røberg, Trondheim Fjord (Arndt, 1913: p. 112, G. mülleri); Korsfjord near Bergen (Norman, 1879: p. 13, Geodia sp.; Brunchorst, 1891: p. 31, Geodia sp., according to Arndt, 1935: p. 30, both G. cydonium); off Haugesund (Schmidt, 1875: p. 120, Geodia gigas, according to Arndt, 1935: p. 30, G. cydonium); off Stavanger (Burton, 1930: p. 490, G. mülleri).
Iceland: 64°56′N, 11°48′W, 216 m, 25.08.1902 (Burton, 1959: p. 9); Faxa Bay (Einarsson, 1941: p. 23, as G. mülleri).
Discussion: Koltun (1966) reinvestigated the specimens of Gorbunov (1946) and Breitfuss (1912) and found that they are G. phlegraei. The specimen of Arndt (1913) could not be traced. A.B.K. and H.T.R. have sampled intensively on the same locality, Røberg in the Trondheimsfjord, and found many specimens of G. barretti and G. phlegraei, but not a single specimen referable to G. cydonium; note that the specimen of Arndt was probably about 15 cm in diameter. We conclude that Arndt’s specimen must have been misidentified. Arndt (1935) referred to some Geodia ‘sp.’s in the literature as G. cydonium. Nothing indicates that Arndt ever saw any of these specimens, rather he just felt certain that G. cydonium was an inhabitant of Norwegian waters. We have worked along most of the Norwegian coast and we have not found specimens that could be referred to G. cydonium. Probably all those referred to above represent G. barretti, which is very common along the entire Norwegian coastline.
The Icelandic records are doubtful, too. We reinvestigated the specimen of Burton (1959) stored at ZMUC; in our opinion it is a fragment of G. barretti. Einarsson (1941) wrote ‘... enormous masses of sponges (G. mülleri ?) are encountered...’ Unfortunately we have no other samples from the same area, but everything considered, if it is a Geodia at all, it is presumably G. barretti.
Our conclusion is that there are no certain records of G. cydonium north of the line Shetland Islands– Lousy Bank, west of the Faroe Islands. The last mentioned locality is listed by Burton (1959), and no description or further reference is given; accordingly, it may also be considered doubtful until a control is possible.