Oliver. — Vegetation of the Eermadec Islands. 153 



extensions of the plants of each island to the other two islands whose plants 

 are tabulated. 



The figures for Lord Howe and Norfolk Island plants are compiled from 

 the lists published by Mr. W. B. Hemsley (9 ; p. 221) and Mr. J. H. Maiden 

 (13 and 14), and corrected with the further notes by Mr. Maidei\ in the 

 Proc. Linn. Soc. N.S.W. 



A comparison of the three tables reveals certain facts which I think can 

 be explained by the geographical position of the islands and the known 

 direction of prevailing winds and ocean-currents in this portion of the Pacific 

 Ocean. 



The proportion of New Zealand species decreases from east to west, 

 while there is a corresponding increase of Australian forms in the same 

 direction. In all cases the Polynesian element is not so important as that 

 of either New Zealand or Australia, the proportion of Polynesian plants not 

 extending to either of the latter regions being small. The large number 

 of Australian plants on Lord Howe and Norfolk Islands is due to the nearness 

 and extent of coast-hne of the continent in a north-and-south direction, and 

 consequently plants have had frequent chances of reaching, and now out- 

 number the New Zealand species in, these islands. The tables show that, 

 of the 27 and 48 purely Australian forms in Norfolk and Lord Howe Islands 

 respectively, only 6 in each case extend to the other island or the Kermadecs. 

 It is evident that the Australian species are more of the nature of stragglers 

 which have accidentally found their way across the ocean. 



The endemic species appear to be more closely allied to New Zealand 

 and New Caledonian than to Australian forms. Lord Howe and Norfolk 

 Islands are in the line of migration of plants and animals (8 ; p. 397 : 

 12 ; p. 19) between Malaya and New Zealand. 



In considering the distribution and relationships of the floras of Lord 

 Howe, Norfolk, and the Kermadec Islands certain species may be disre- 

 garded — for instance, all the sporiferous plants, and a host of Australian 

 and other species belonging to widely distributed genera. The remaining 

 genera are here enumerated for the purpose of showing the true affinities 

 of these insular floras. 



Araucaria excclsa, R. Br., of Norfolk Island, resembles A. Cookii, R. Br., 

 of New Caledonia, and A. Cunninghamii, Ait., of Queensland and New 

 South Wales. 



Pandanus Forsteri, C. Moore and F. v. Muell., in Lord Howe Island, is 

 allied to a Malayan species (P. odoratissimus). 



Freycinetia and Cordijline are Oriental genera reaching as far as Queens- 

 land and New South Wales in one direction, and Norfolk Island and New 

 Zealand in another. 



Howea, a genus of two species confined to Lord Howe Island, is ap- 

 parently related to Australian and Malayan forms. CUnostigma contains 

 one species in Lord Howe Island, and three or four in New Caledonia and 

 Samoa. 



Rhopalosti/lis includes two species — one in New Zealand, the other con- 

 fined to Sunday and Norfolk Islands. Hedyscefe, monotypic in Lord Howe 

 Island, is related to Rhopalostylis. 



Phormium is confined to New Zealand and Norfolk Island. 



The tropical genus BoeJimeria has three closely allied endemic species in 

 Lord Howe, Norfolk, and the Kermadec Islands (one in each group), but 

 does not extend to either New Zealand or Au^stralia. 



