of the Galapagos Archipelago. 25 1 



Galactia, Opuntia, Cereus, Fiscum, all the new genera of Compositce, besides 

 Aphpappus and Hemizonia, species of Ipomcea, Psidium, Cordia, Tournefortia, 

 Croton, Peperomia, Epidendrum, Eutriana and Aristida. Those belonging to 

 the Savannah lands of the United States, or dry parts of the tropics rather than 

 the damp, hot, low grounds, are 24 (out of the 45) of Poly gala, Galapagoa, 

 Elaterium, Sicyos, 7 species of Borreria, 6 of Acalypha, and 5 of Euphorbia, 

 besides a Brandesia and Altemanthera. Thirteen from the following genera, 

 though very distinct, are exceptional, as being allied to plants of the same range 

 as those included in the West Indian type; they belong to Desmodium, Pha- 

 seolus, Acrolasia, Pleuropetalum, Pisonia, Froelichia, 3 species of Bucholtzia, 

 Mariscus, Cyperus, and Paspalum. 



If, on the other hand, the species common to other parts of the world, 

 including those which are possibly allied, be contrasted with the above, they 

 will be seen to belong to a different type of vegetation, being inhabitants of 

 hot, low and marshy countries, or purely littoral species ; they amount to 

 120, 88 of which are natives of the West Indies or Southern United States. 

 Again, of these, 35 are common to the old and new world, affording no evi- 

 dence of botanical relationship to any country ; whilst the following 26, some 

 of them remarkable species, are particularly prevalent over the Caribbean Sea, 

 Gulf of Mexico and Galapagos. 



Paritium tiliaceum. Spermacoce tenuior. 



Sida rhombifolia. Wedelia frutescens. 



Gossypium purpurascens. Spilanthes Acmella. 



Malachra capitata. Convolvulus alsinoides. 



Turnera ulmi/olia. Lantana recta. 



Xanthoxylum pterota, Varronia dasycephala. 



Mimosa asperata. Hyptis capitata. 



Parkinsonia aculeata. Heliotropium Indicum. 



Poinciana pulcherrima. Phyllanthus obovatus. 



Tephrosia littoralis. Urtica Canadensis. 



Rhynchosia reticulata. divaricata. 



minima. Poa pilosa. 



Chiococca racemosa. Digitaria serotina. 



Of the remainder of the 120, the following I have assumed to be confined 



VOL. XX. 2 L 



