INTRODUCTION TO THE REPORTS ON INSULAR FLORAS. 



35 



total endemic genera for the different areas of Tropical America is &22 (p. 190). Adding 

 to this number the genera extending to two or more of the areas, but not beyond 

 Tropical America, the proportion of endemic genera must be even higher than in 

 Australia. 



With regard to the proportion of endemic species in oceanic islands compared with 

 continental areas, it will be seen that it is higher in Australia, and doubtless as high iu 

 South Africa and in some parts of South America, as well as in Mexico. 



PROPORTION OF MONOTYPIC ENDEMIC GENERA TO THE TOTAL ENDEMIC 

 GENERA IN VARIOUS ISLANDS AND CONTINENTAL AREAS. 



The following are the monotypic endemic genera in the remote oceanic islands dealt 

 with in this work : Ncsiota, Petrobium, and Mdlissia in St Helena ; Pringlea in the 

 chain, if we may so term it, of islands, from the Prince Edward group to the Macdonald 

 group ; Lyallia in Kerguelen only ; and Rhctinodendron, Sdhirhia, Lactoris, Ochagavia, 

 Juania, Pantathera, and Podophorus in Juan Fernandez : the total endemic genera being 

 respectively five, two, and ten. For comparison, we extract from Engler (he. cit., p. 

 133) some particulars of the proportions in various other parts of the world, intercalating 

 our own ; limited, however, to the dicotyledons : — 



The percentages of monotypic genera for East Australia and New Caledonia are given 

 by Engler as 65 and 47 respectively, evidently through some clerical error. The five 

 Japanese endemic genera which are not monotypic are all ditypic ; while eleven of the 

 New Caledonian and sixteen of the Madagascar endemic genera are also ditypic. 



1 Adding the monocotyledons the percentage rises to 70. 



