AECTIC PEOYHS'CE. 57 



I. Abctic Provhtoe. 



The NortL. Polar Seas contain but one assemblage of MoUusca, 

 •whose Southern limit is formed by the Aleutian Islands in the 

 Pacific, but in the North Atlantic is determined chiefly by the 

 boundary of floating ice, descending as low as Newfoundland 

 on the West, and thence rising rapidly to Iceland and the North 

 Cape. A very complete general account of the Arctic Mollusca 

 is given by Dr. Middendorff ; * those of Greenland have been 

 catalogued and described by Otho Fabricius and Moller ;t and 

 more recently by Morch •,% 158 species are enumerated by 

 Middendorff, and 202 by Morch. Scattered notices occur in 

 the Annals of Natural History, § and the Supplements to the 

 Narratives of the Arctic Voyagers, — Phipps, Scoresby, Franklin, 

 Back, Ross, Parry, and Eichardson. The existence of the same 

 marine animals in the Kamtchatka Sea and Baffin's Bay was 

 long since held to prove at least a former North-West passage ; 

 but the occurrence of recent sea-shells in banks far inland 

 rendered it probable that even recent elevation of the land in 

 Arctic America might have much reduced the passage. During 

 the " Grlacial period," this Arctic Sea, with the same fauna, ex- 

 tended over Britain ; over Northern Europe, as far as the Alps 

 and Carpathians ; and over Siberia, and a considerable part of 

 North America. The shells now living in the Arctic Seas, are 

 found fossil in the deposits of "Northern Drift," over all these 

 countries ; and a few of the species yet linger within the bounds 

 of the two next provinces, especially in tracts of unusual depth. 

 The Arctic shells have mostly a thick greenish epidermis (p. 33) : 

 they occur in very great abundance, and are remarkably subject 

 to variation of form, a circumstance attributed by Professor E. 

 Forbes to the influence of the mixture of fresh water produced 

 by the melting of great bodies of snow and ice. 



AUCTIC SHELL-PISH. 

 E. Eussian Lapland. F. Finmark. L Iceland. G-. Greenland. D. Davis Straits (west 

 coast). B. Behring's Straits. 0. Ochotsk. * British species (living). ** British 

 species (fossil). 

 Octopus graniilatus. G. | „ amoena. G-. 



Cirroteutliis MiiUeri. G. *Oirmiastrephes todarus. F. Newf. 



Eossia palpebrosa. G. P. Eegent Inlet. I 



Onychoteiithis Bergii. F. B. Limacina arctica. G. 0. 



„ Fabricii. G. 



* Malaco-zoologiaEossica; Mem. del' Acad. Imp. des Sc. Petersb. T. 6, pt. 2, 1S49. 

 t Index Molluscorum Groenlandise. Hafn. 1842. 



t Fortegnelse over Grcinlands Bloddyr in H. Rink : Gronland geographisk og statia- 

 tisk beskrevet, ii. Bind. 1857. 

 $ Hancock, An. Nat, Hist. vol. 18, p. 323, pi. 5. 



