CATALOGUE OF MABINE ALG^ OF WEST INDIAN KEGION. 43 



I venture to think tliat the conclusion is obvious enough, from 



the foregoing tables, that the West Indian Region is a natural one. 



At the beginning of the work the inclusion of Bermuda in the region 



seemed to rest on doubtful grounds, but on the whole, these doubts, 



such as they were, have been removed during its progress. The 



occurrence on that island of two species of Fucus, for example, viz., 



F. ceranoides L. and F. distickus L., certainly makes one pause, but 



a consideration of the whole of the list containing many examples 



of peculiar West Indian forms outweighs this evidence of a northern 



flora and we may safely regard Bermuda as no longer "vexed," 



but well established as the northern limit down the Gulf Stream of 



this region. The other difficulty in delimiting the frontier of the 



West Indian Eegion has been the wide question of how far it is 



worth while separating it from the warm Atlantic region. It will 



be seen that the latter exceeds by only one the total for the 



Mediterranean of West Indian forms common to the regions in 



question but it must not be forgotten that the Mediterranean not 



only offers a long coast-line, but it has been far better explored for 



Algas than the coast-lines of the warm Atlantic region. Compare 



our knowledge of the Algas of the Adriatic or of the Bay of Naples 



with our poor records from Brazil or the West African coast ! 



The proportion of warm Atlantic forms occurring in the West 



Indies (to put the case from the other point of view) I mean the 



proportion to the whole known marine flora is far greater than the 



proportion of Mediterranean forms so occurring. While therefore 



maintaining the West Indian region for the present, I should offer 



no serious opposition to its being engulphed in the warm Atlantic 



region if it be considered desirable to deal with regions of larger 



area. 



The total of species common to the Cape may cause some 

 surprise as to its smallness compared with Australia. This, I take 

 it, is to be accounted for by the two facts that Australia has been 

 ascertained to have a very large and varied marine flora, and that 

 this flora has been so thoroughly studied from the systematic point 

 of view. From Australia and the S. Pacific, I should explain that I 

 exclude North Australia. The material from Torres Straits, which 

 is about all we know of it, shows a greater relationship with Indian 

 Ocean and warm Pacific forms than with East, South, or West 

 Australian forms. The smaller totals from warm Pacific and 

 North Pacific are to be accounted for by the poverty of our 

 knowledge of these regions. 



The total from the Indian Ocean is at first sight most surprising 

 of all in its being smaller than the Australian total. I have 

 included in this Indian Ocean region, the Bed Sea, and islands, &c., 

 as far south as Mauritius, and as far east as Singapore. Granted 

 that the Australian marine flora is well known, it must also be 

 urged that the Indian Ocean as thus delimited has been by no 

 means neglected. Allowing that, of the two regions, Australia is 

 the better known, even then the result is surprising when we 

 consider the similarity of the physical conditions occurring in the 

 Indian Ocean and West Indian regions and the enormous extent 



