520 ON THE FAUNA AND BOTTOM-DEPOSITS NEAR THE 30-FM. LINE 



whilst those which have only been recorded from the Boreal by B. The 

 letters L.B. denote species extending from the Mediterranean to 

 the north of Norway, Iceland, and often to the eastern coast of America. 

 The letter L. indicates that the species has its centre of distribution in 

 the Lusitanian province, but such species may extend up the western 

 coasts of the British Isles to Shetland, or even to the southern parts of 

 Scandinavia. 



In Table VII., p. 536, the total number of species falling under each 

 of these heads is given for the various groups of animals obtained during 

 the present investigation, all of which, therefore, live at a depth of about 

 30 fathoms between Start Point and the Eddystone. In each case also 

 the percentage of animals belonging to the group, living in each region, 

 is added. 



Eegarding this fauna as a whole, it will be seen that the prevailing 

 element is southern, or Lusitanian ; 56 per cent, falling under the heads 

 of L. and L.B., and 30 per cent, under L. alone, whilst only 26 per cent, 

 come under A.B. and B. Eight per cent, of the recorded species occur 

 in the Arctic and Boreal regions only, whilst 18 per cent, have a very 

 wide range, extending from the Arctic to the Mediterranean. 



Looking at the figures for each group (excluding those in which 

 the number of species is too small to give reliable results), it may 

 be noticed that the fishes and Crustacea show the southern element 

 most markedly, whilst the Hydrozoa and Polyzoa are remarkable 

 for the number of species which have a very extended range. 



In a subsequent paper I hope to compare the figures obtained for 

 species living at 30 fathoms with similar ones for species extending 

 from the shore to about 15 fathoms. 



