THE EUROPEAN SEAS. 



55 



find which alive in the European seas, we must now 

 travel to the bounds of the Arctic Ocean — combined 

 with the absence of the great body of Celtic species, 

 has a significance of deep import. Not even on 

 the verge of the Arctic province are we to seek 

 for the analogue of the fauna of the drift, but 

 within its strictest bounds. Of this, however, more 

 hereafter. 



The number of mollusca recorded from the coasts 

 of Finmark, affords an indication of the degree of 

 fertility of that region in species. There are three 

 Cephalopods, of which one is peculiar and new ; 

 three Pteropods, one of them ranging as far south as 

 Scotland ; four Nudibranchs, two of them peculiar ; 

 sixty-six univalve Testacea, of which thirty-six range 

 as far south as the British seas, or farther ; four 

 Brachiopoda, one of which is new ; and forty-five 

 ordinary Bivalves, of which all but eight range to 

 the British seas ; making a total of one hundred 

 and sixty-nine species. This number is consider- 

 ably larger than that of the Greenland molluscan 

 fauna, which amounts to one hundred and thirty- 

 four species. The difference is due to an infusion 

 of species advancing from the south, along the 

 continuous shores of Norway, in the one case, 

 whilst the Arctic fauna is isolated on the other. 

 The Greenland number is therefore a truer expres- 

 sion of the Arctic molluscan fauna (exclusive of 

 Tunicata, which I have not counted in either case), 

 than the Finmark number. The authorities I 



