OP wester:n' south amebica. 145 



It will be noticed that, witla a single exception, all tlic plants in 

 the above list belong to genera that are widely spread throughout 

 equatorial America, and that, including two new s^^ecies and one 

 doubtful, there are but seven species probably confined to the 

 Pacific coast. It is extremely difficult to collect materials for 

 comparison, inasmuch as the excellent, but uufinished, ' Prodro- 

 mus Flora) NoA^o-Granatcnsis ' of MM. Triana and Planchon 

 includes only the Natural Orders of Thalamiflora), probably little 

 more than one tenth of the entire flora. I have analyzed the 

 contents of the volume, omitting the mountain-species and taking 

 account only of the genera which are represented in the warm 

 zone of the Pacific coast, which may be reckoned to extend from 

 the shore to a height o£ about 1500 metres, and I find that the 

 DO genera enumerated may bo divided into the following cate- 

 gories : 



G genera cosmopolitan, i.e. widely spread throughout the 



world. 

 38 ,j amphigean, i. e. in the tropics of both hemi- 

 spheres. 

 46 „ tropical American, extending widely througli 



the continent. 

 D „ endemic, not extending far from the Pacific 



coast. 



Total 99 



Several of the genera ranked as ampliigean are represented in 

 tropical America and tropical Africa, but not elsewhere in the 

 world. A few of the tropical-American genera extend to the 

 temperate zones in ]N"orthor South America. The large majority 

 extend to Brazil ; but a few (four or five) do not apj^ear to range 

 beyond Guiana. It must be remembered, however, that tin's 



implies a range of at least 1600 miles from east to west, while the 

 great majority extend over au area of at least 3000 miles in 

 diameter. 



The endemic genera are those demanding most attention. 



Hampea and Matida are genera belonging to the tribe Bom- 



hacece^ which is, in many respects, intermediate between Malvacccs 



and Sterculiacece. Along wuth two genera which are common to 



the tropics of tlie Old and Ncav AVorld, this tribe has developed 



. XI number of forms so distinct that they have been ranked as 



