434 MR. G. BENTHAM ON COMPOSIT f. 
3. MELAMPODINES, nineteen or twenty genera and nearly 100 
species, constitute a more definite subtribe, intermediate between 
Milleriee and the great mass of Helianthoidee (Verbesineg), 
differing from the former in their completely paleaceous receptacle, 
from the latter in the constant sterility and undivided styles of the 
disk-florets. They are, with two exceptions, exclusively American 
and chiefly tropical, but occasionally extending further both north- 
ward and, in a less degree, southward. Most of them require here 
but a very short mention. Ichthyothere, eight species, Baltimora, 
two species, and Acanthospermum, two species, are strictly tropical 
and chiefly eastern ; Melampodium, eighteen species, is also tropical, 
but with a much wider range, extending northwards over the 
Mexicano-Texan region, with one species (probably introduced) 
found also in various parts of the warmer regions of the Old 
World, and another, to all appearance really indigenous, in the 
Philippine Islands. —Espeletia, eleven species, Philoglossa, one or 
two species, and Schizoptera, one species, are also South-American 
and tropical, but limited to the Andes; Parthenium, six species, 
and Polymnia, twelve species, are tropical, but also extratropical 
and chiefly, but not entirely, western, the former extending from 
Chili to the Mexican region, the latter from the Argentine 
Republic to Canada. Eight genera are limited to the Mexican 
region, — Berlandiera, with five species, Guardiola, with four, Tri- 
gonospermum, with two species, and the monotypic Lindheimera, 
Engelmannia, Dicranocarpus, Aiolotheca, and Parthenice. Another 
monotypic genus, Lecocarpus, is limited to the Galapagos Islands; 
Silphium, with eleven species, is exclusively North-American. This 
geographical arrangement is, however, not in conformity to struc- 
tural affinities ; the natural divisions of the subtribe have generally 
a wide range. The northern Silphium, the Andine Schizoptera, and 
theintermediate Berlandiera, Lindheimera, and Engelmannia might 
form one genus, which would then have as extended an area as 
Polymnia. The east tropical Acanthospermum and the Galapagian 
Lecocarpus might be included in the widely spread Melampodium. 
There remains the genus Chrysogonum, which, although it is 
undoubtedly nearly related to Silphium, and has even one species 
belonging to the same area in North America, is yet more 
strongly represented in a widely distant region; two species are 
East-Indian and three are tropical-Australian. "These Old-World 
species have been hitherto known under the name of Moonia; but, 
on attempting to draw up comparative characters in the subtribe, 
