444 MR. G. BENTHAM ON COMPOSIT X. 
the Andes of Peru as far as Chili, but far more numerously by the 
Central-American genus Tithonia, three or four species, and the 
general tropical-American Viguiera, of about sixty species, both of 
which are, on the one hand, somewhat artificially distinguished 
from Helianthus, and, on the other hand, pass almost into the 
already-mentioned tropical Wedelia group, or into a few of the 
smaller Mexican or tropical genera which I shall presently 
refer to. 
Confined to the Mexican region we have nine or ten genera of 
one or two species each :— Rumfordia, Selloa, Aximiphyllum ( Aba- 
saloa ?), Varilla, Chromolepis, Mirasolia, lostephane, Otopappus, 
and Podachenium, to which we may add the Coreopsideous genus 
Coreocarpus, also of two species only. Small as they are, I do not 
think that any of these genera are sufficiently connected with any 
of their large cotribuals to be incorporated with them, unless these 
again be much more consolidated ; nor do they form of themselves 
a separate group in the subtribe. Like so many others of the 
same region, they may be considered as the scattered remnants of 
various ancient races. The distinct genus Encelia, which, taken 
in its natural extended limits, comprises twenty-two species, is 
also Mexican, but extends southwards and northwards from Chili 
to California. 
In the insular genus Scalesia, eighteen or ten Galapagian 
species, may be traced a connexion with the above mentioned 
Mirasolia, which belongs to the southern or Central-American 
portion of the Mexican region. 
In the South-American Andes we have again four genera of 
one or two species each :—Monactis, Stemmatella, Aphanactis, and 
Garcilassa, as much if not more isolated than those of the Mexican 
region, none of them having any nearer connexions than the 
general affinity to the whole subtribe. Pascalia, a monotypic 
genus of the same region but more southern, and quite or nearly 
extratropical, is generally allied to the Wedelia group. 
Among tropical-American Verbesinex, besides those already 
mentioned as connected with the North, the most important is 
Verbesina itself, with about fifty species, dispersed over the whole 
region, and represented by several species in North America, and 
one or two extending beyond the tropies to the south. One 
species, distinguished by most authors on very trifling characters 
under the name of Ximenesia, is met with in tropical Africa and 
some other warm countries, but evidently introduced from America, 
