214 



APPENDIX. 



The eighty-five genera in the foregoing list constitute about 4*6 per cent, of the 

 total in Mexico and Central America, and they comprise 39 per cent, of the species. 

 There is a very great disparity in the proportions, and it is evident that most of these 

 genera abound in individuals as well as species, and constitute a large part of the vege- 

 tation, some in one region and some in another. Yet when it is remembered that such 

 important types as pines, tree-ferns, myrtles, laurels, mangroves, nearly all the genera 

 of palms, all the genera of the Yucca type except Agave, and a host of other prominent 

 things do not come under consideration by reason of their numerical inferiority in 

 species, the part the large genera play will be more accurately appreciated. Indeed, 

 so far as mere domination is concerned, it is certain that several of the genera of a 

 single species surpass others of a hundred species, either in consequence of their size or 

 prodigious individual development. 



Monotypic Genera. 



We pass from the strongly diversified genera to genera of a single species. Some of 

 these might, perhaps, with equal justice rank as anomalous species of other genera ; 

 but, as a whole, they consist of distinct isolated forms whose origin and isolation may 

 be due to a variety of causes and accidents ; but we do not propose entering into any 

 speculations on this subject here. It would fill too much space to enumerate the 

 genera ; but the numbers in each order, with the orders systematically arranged, will 

 serve both as an index to them and present them to the eye in a more intelligible 

 manner than a sum total would do. 



Number of Monotypic Genera in each Natural Order and their Distribution. 



Orders. 



Total. 



Endemic. 



Extending to other parts 

 of America. 



Extending 



beyond 



America. 





1 

 1 

 1 

 1 

 3 

 2 

 1 

 1 

 2 

 1 

 4 

 2 

 1 

 2 

 2 

 5 



30 



1 



1 

 

 1 

 1 





 



1 





 

 2 

 2 

 

 2 

 2 

 4 



1 widely. 



2 N.W. & N.E. 



1 JS7W. &S.; and 1 S. & W. I. 

 1 S. 



1 N. W. ; 1 widely. 



1 S 



1 widely ; 1 S. & W. I. 



1 S. & W. I. 

 1 N.W. 



1 

 1 

































17 



13 



2 



