DISTRIBUTION OF TRIBES. 449 
closely connects Tagetines with Senecionidez, that it is difficult 
to determine to which it should be referred. The aspect and 
most of the characters, as well as geographical considerations, 
tend towards Tagetinee; but there appear to be no oleaginous 
glands. Both the species require further investigation from more 
perfect specimens. 
-Euheleniee, seven genera and about forty-five species, all 
American, are chiefly extratropical; they form in some instances 
a near approach to Anthemides, and may be generally con- 
sidered as the American representatives of that Old- World tribe, 
although in a very few species they also show an approach to 
Senecionidex. Structurally they differ from the preceding sub- 
tribes, chiefly by their shorter silky-villous achenes, and by their 
broader, more open, and sometimes Anthemoid involucres. The 
principal genera are not in N. America so specially Mexican 
as most Helenioides, but spread more equally to the east- 
ward. They generally, if taken with their most natural limits, 
include in one genus species with fertile or sterile ray-florets, or 
without any at all. Under this view Helenium, with about six- 
teen N.-American species, may be said to be represented in 
extratropical S. America by Cephalophora, four or five species ; 
Gaillardia, with five N.-American species, has a sixth extra- 
tropical southern one (Gúntheria). Actinella with ten species is 
confined to N. America; but Hymenoxys, four species, which is 
nearly related to it, but with a more Anthemoid aspect, is both 
in extratropical S. America and in the Mexican region. 
Psathyrotes, a Mexican genus of three species, has much of the 
involucre and pappus of a Senecionidea; but the achenes and 
some other characters are those of the Euheleniew, and the 
closely allied monotypic Trichoptilium, from California, connects 
it with the latter in the pappus also. 
There remain four genera, which, on account of their involu- 
cral bracts, imbricate in several rows, increasing from the outer 
to the inner, are anomalous in Helenioidex, and are artificially 
placed in a separate subtribe, Jaumiee. Two of them, Cacosmia 
four or five species, and Geissopappus two species, are from tropical 
Ameriea, and correspond in many respects to the Helianthoid 
genera Calea and Galinsoga from the same region, but have the 
naked receptaculum and the achenes of Helenioidese. Jaumea 
isa small genus which appears to me as distinct in habit and 
character as it is remarkable for its scattered geographical distri- 
2x2 
