cnAP. XV THE SAXDWICH ISLAXDS 325 



positse are really confined to the Archipelago. The rela- 

 tions of the peculiar genera and species are indicated in 

 the following table. ^ 



Affinities of Hawaiian Composites. 



Xo. of 

 Peculiar Genera. Species. External Affinities of tlie Genus. 



Remya 2 Very peculiar. Allied to the North American 



genus Grindelia. 



Tetramolobium ... 7 South Temperate America and Australia. 



Lipochseta 11 Allied to American genera. 



Campylothreca ... 12 With Tropical American species of Bidens and 



Coreopsis. 



Argyroxipliium... 2 With the Me.vican Madiese. 



Wilkesia 2 Same affinities. 



Dubantia 6 With the Mexican Raillardella. 



Raillardia 12 Same affinities. 



Hesperomannia... 2 Allied to Stifftia and Wunderlichia of Brazil. 



Peculiar Species. 



Lagenophora 1 Australia, New Zealand, Antarctic America, Fiji 



Islands, 



Senecio 2 Universally distributed. 



Artemisia 2 Xorth Temperate Regions. 



The great preponderance of American relations in the 

 Compositse, as above indicated, is very interesting and 

 suggestive, since the Compositse of Tahiti and the other 

 Pacific Islands are allied to Malaysian types. It is here 

 that we meet with some of the most isolated and remark- 

 able forms, implying great antiquity ; and when we con- 

 sider the enormous extent and world-wide distribution of 

 this order (comprising about ten thousand species), its 

 distinctness from all others, the great specialisation of its 

 flowers to attract insects, and of its seeds for dispersal by 

 wind and other means, we can hardly doubt that its origin 

 dates back to a very remote epoch. We may therefore 

 look upon the Compositae as representing the most ancient 

 portion of the existing flora of the Sandwich Islands, 

 carrying us back to a very remote period when the facili- 

 ties for communication Avith America were greater than 

 they are now. This may be indicated by the two deep 

 submarine banks in the North Pacific, between the Sand- 

 wich Islands and San Francisco, which, from an ocean floor 



^ These are obtained from Hildebrand's Flora supplemented by Mr. 

 Bcntham's paper in the Journal of the Lin/iean Society. 



