114 Transactions. 



The non-endemic species are mainly widely distributed forms with a 

 large proportion of Australian types. The distribution of these species is 

 as follows : New Zealand only, 5 ; Australia only, 27 ; Polynesia only, 4 ; 

 New Zealand and Australia, 28 ; New Zealand and Polynesia, 2 ; Australia 

 and Polynesia, 36 ; all three regions, 37. (The more extended distribution 

 of most of the species is here not taken into account.) I believe that with 

 every species common to Lord Howe Island and one or more of the adjacent 

 regions there is a suspicion of immigrants having from time to time been 

 received across the intervening tract of ocean ; consequently, if it be 

 assumed that the greater number are capable of being transported across 

 wide expanses of ocean, their presence must not be regarded as supporting 

 a land connection. 



Geographical. 



The New Zealand element in the Lord Howe Island flora is important, as 

 it includes two (Cohneiroa and Hedyscepe) of the four endemic genera, to 

 which should perhaps be added a third (Negria). A highly characteristic 

 New Zealand genus, Carmichaelia, with nineteen species in that country, has 

 a twentieth in Lord Howe Island. Other genera represented in Lord Howe 

 Island by endemic species related to New Zealand species include Coprosma. 

 Sideroxylon, Dracophyllum, Senecio, Pittosporum, Melicope, and Pimelea ; 

 while amongst those species restricted to the two places are Uncinia fili- 

 formis, Hymenanthera novae-zelandiae, and Gahnia xanthocarpa . 



The Polynesian element stamps the flora as distinct from that of New 

 Zealand. The genera include important members of the flora, two of them. 

 Acicalyptus and Clinostigma, being dominant in their respective habitats : 

 while Boehmeria is not now common, but is suspected of having been de- 

 stroyed in many places by introduced pigs. Metrosideros nermdosa, Alyxia 

 squanndosa, Alyxia Lindii, and Symplocus candelabrum are endemic species 

 related to Polynesian forms ; while confined to Lord Howe Island and 

 Polynesia are Metrosideros villosa. Tecorna austro-caledonica, Zanthoxylum 

 pinnata, and Blechnum attewuatum. 



The Australian element, considered numerically, is considerably larger 

 than either the New Zealand or Polynesian. But the proximity of the 

 Australian Continent, its great extension in a north and south direction, 

 and the direction of the prevailing winds in the south-west Pacific Ocean 

 no doubt account for this preponderance. The genera confined to Australia 

 and Lord Howe Island are Notelaea, Lyonsia, Melaleuca, Lagunaria, and 

 Westringia. It may be noted here that the most characteristic Australian 

 genera are either entirely absent from Lord Howe Island or represented by 

 one or two species only. The species occurring in Australia and New 

 Zealand but not in Polynesia may have entered Lord Howe Island from 

 either country, and show a latitudinal dispersal in the Temperate Zone 

 independent of that in subtropical regions, indicated by the widely distri- 

 buted tropical species not extending to New Zealand. 



Moraea is known only in Africa and Lord Howe Island. It is a remark- 

 able case of discontinuous distribution, and possibly the Lord Howe Island 

 form is a relict species indicating a former wider distribution of the genus. 



If we consider only the species which, occurring in Lord Howe Island, 

 extend to one only of the regions named, and also those endemic forms 

 related to species having a similarly restricted distribution, we find that 

 for Polynesia and New Zealand the ratio of endemic to non-endemic species 

 is 2 or 3 to 1, while for Australia it is less than J to 1. Here again, 



