154 Transactions. 



Colmeiroa, a monotypic genus confined to Lord Howe Island, is allied 

 to the endemic monotypic Carpodctus of New Zealand. 



Carniichaelia, a characteristic New Zealand genus of nineteen species, 

 has a twentieth in Lord Howe Island. Streblorhiza, endemic in Norfolk 

 Island, is related to Carmichaelia. 



Homolanthus is a Malayan and Polynesian genus. It extends down 

 the east coast of Australia, to New Caledonia and Lord Howe Island, 

 and in a peculiar species to the Kermadecs. 



Corynocarpus contains two species — one in New Zealand and the Ker- 

 madecs, the other in New Caledonia and the adjacent islands. 



The Norfolk Island endemic genus Unyeria is related to Reevesia of the 

 Oriental region. 



Melicytus has four species in New Zealand, one of which extends to 

 Norfolk and Sunday Islands and Eua (a small islet in the Tonga Group). 



Acicalyptus has one species in Lord Howe Island, another in Fiji, and 

 three in New Caledonia. 



Metrosideros is a Malayan and New Zealand genus. The Polynesian 

 species, M. villosa, extends to New Caledonia, Lord Howe Island, and the 

 Kermadecs. 



Meryta has ten species in New Caledonia, two in Norfolk Island, one in 

 New Zealand, and two or three in the Pacific islands. 



Negria, a monotypic genus confined to Lord Howe Island, is allied to 

 Ehabdothammis, monotypic in New Zealand, and both are near Coronanthera 

 of New Caledonia. 



Coprosma, a characteristic New Zealand genus, is represented in Lord 

 Howe Island by three species, in Norfolk Island by three species, and in 

 the Kermadecs by two. C. petiolata of the Kermadecs is closely allied to 

 C. Baueri of Lord Howe Island, Norfolk Island, and New Zealand. 



Lagunaria (scarcely distinct from Hibiscus) is monotypic in Qiieensland, 

 Lord Howe and Norfolk Islands. Besides this genus only three others 

 strictly Australian extend to Lord Howe Island. These are Smilax, Notolcea, 

 and Westringia, each represented by one species, of which the Notolcea is 

 peculiar. It should be pointed out that the most characteristic Australian 

 genera are either entirely absent, or represented by one or two species only. 

 For instance. Acacia, Eucalyptus, Melalauca, Leucopogon, Grevillea, and 

 Hakea together contain about 900 species, and form a large part of the 

 vegetation in the eastern portion of tho continent, yet only two species 

 [Melaleuca ericifoUa and Leucopogon Richei) have found their way to Lord 

 Howe Island. 



The floras of the three islands under consideration are fragmentary, 

 but on account of the isolated positions of the islands this would be expected. 

 Further, the geological structure does not support the supposition that 

 the islands are the remnants of a large land-mass, nor does there appear to 

 be a plant formation on any one of them that one might suspect to be 

 a fragment of a once more extensive forest. At the same time it is im- 

 possible to believe that all the plants populating these islands have crossed 

 the wide stretches of ocean now separating them from the nearest land- 

 masses. 



In view of the presence of the genera above enumerated, of the com- 

 munity of genera and species of each island Avith the other two, and the 

 relation of the same to those found in the three adjacent biological regions 

 as expressed in the foregoing tables, the following are suggested in explana- 

 tion of the origin of these insular floras. 



