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CHAPTER IX. 



ON THE DISTRIBUTION OF MAEINE ANIMALS. 



The assemblages of animals composing the fauna 

 of the European seas have been shown to undergo 

 a constant change from place to place. The dif- 

 ferences and peculiarities are broad enough in cer- 

 tain cases to be seen by those who commonly bestow 

 but little attention on such matters. Thus the pe- 

 culiarity of the fishes of Mount's Bay would be 

 recognised at once by any one who had only seen 

 those captured on the coasts of Norfolk ; and the 

 abundance of the elegant Nephrops in the Dublin 

 market would arrest the attention of the epicure 

 whose experience had been limited to the edible 

 Crustaceans of the London fish-stalls. 



This system of change, or of geographical distri- 

 bution, has of late acquired a great amount of in- 

 terest ; it is connected with some of those curious 

 inquiries into bygone conditions of the earth's sur- 

 face which are now undergoing investigation, so that 

 the subject forms a necessary part of the natural 

 history of each separate province ; and although 

 we may not as yet have arrived at a satisfactory 

 knowledge of all the conditions which bear upon 

 this enquiry, it may not be amiss to consider some 



