THE EUKOPEAN SEAS. 



285 



graduating from one to another much more truly 

 represents the relations of these assemblages. 



The great "Arctic" fauna is here indicated by 

 light blue ; a darker tint has been taken for that 

 modification of the Arctic fauna which has been 

 described as " Boreal." 



On the south — the West African marine province 

 —from the Senegal river, as far as 25° north lati- 

 tude, is coloured orange, which, about the Canary 

 islands, passes into yellow. This is the furthest 

 extension which can be given to the marine fauna 

 which has been described as " South Lusitanian." 

 In a northerly direction the Lusitanian province 

 reaches to the Channel Islands, and includes every 

 portion of coast from the Azores to the Black Sea. 



The " Celtic " area is coloured green — the blend- 

 ing of the colours of the provinces on either side, 

 as the fauna is composed of the commingling of the 

 forms of those provinces. 



The " Boreal " outliers along the west of our 

 Celtic province are indicated by their appropriate 

 dark blue, and the " Celtic " outlier of Vigo Bay 

 (p. 105) by green. 



The Caspian province, with its outliers at the 

 mouths of the Danube and the Don, are distin- 

 guished by sienna. 



The line of " Floating Weed " in the Central 

 Atlantic has been laid down from the small map to 

 the Memoir in which Ed. Forbes first made known 



