62 NILS ODHNER, NORTHERN AND ARCTIC INVERTEBRATES. III. OPISTHOBRANCHIA ETC. 



Pleurobranchus plumula (Montagu 1803). 

 Habitat: 



West coast of Sweden: Bohuslän, Kosterrännan (June 1893, Ekman) 1 sp. 



Genera] distribution : 



Norway: The west coast 100 — 150 fms (G. 0. Sars 1878); Nordfjord near Ma- 

 trog, 60 fms (Grieg 1897). British coasts (Forbes & Hanley 1853; Jeffreys 1867). 



— France (Vayssiere 1901). - Mediterranean and Adriatic (Cams 1889). — Portugal 

 (Nobre 1905). Madeira (Watson 1897). — Azores (Bergh 1899). — Lower California 

 (Bergh 1894). Depths to 150 fms. Stones, alga?. 



Tylodina Duebenii Loven 1846. 

 Habitat : 



Norway: Bergensfjord (Koren) 1 sp., 200 fms G. O. Sars 1868. 



General distribution: 



Denmark: Helleb^k (Petersen 1889). 



Colpodaspis pusilla M. Sars 1870. 



Distribution: Norway: Dröbak; Horten; 14 — 80 fms (M. Sars 1870). — Plymouth, England (Garstang 1894). 



Colobocephalus costellatus M. Sars 1870. 



Distribution: Norway: Dröbak; Vallö; 70- 230 fms (M. Sars 1870). 



Tritonia Hombergi Cuvier 1802 

 (inch var. alba Alder & Hancock 1855). 

 PL li fig. 18; Pi. Ill fig. i. 



Habitat: 



West coast of Sweden: Skäne between Väderön and Höghalla udde, 10 fms, 

 algae ("'A 1902, Lönnberg) ] sp. — Vinga, Göteborg Skärgärd, sand, 1 sp. (Mus. G.). 



— Bohuslän: ')Gullmarn, numerous sps. (inch var. alba); D:o 50 m, many young 

 sps. ; D:o N. of Flatholmen 18—27 m, alga?, 5 sps.: D:o Löken 22 fms, 3 sps. (Mus. 

 G.); -) Väderöarna (1881 and 1882) 3 sps.: 3 ) Lin dö, near Kosterrännan, 30 fms 

 (Olsson) 2 sps.; ') Strömstad (1882, Hanson) 1 sp. ; "')Dyngö, Fjällbacka 1 sp. 



England: Cullercoats (Alder) 1 sp. (var. alba). 

 Reef of Jutland 50—150 fms (1874) 1 sp. 



