1961] 
Darlington — Australian Carabid Beetles 
23 
in New Guinea Agonini are dominant, with considerably more than 
ioo known full species (some discovered since my 1952 paper) 
against about 40 species of Pterostichini (manuscript in press), a 
reversed ratio of about 3/1. 
One reason for the number of Agonini in New Guinea is that 
species of this tribe have multiplied on the mountains there. In 
Australia, however, Pterostichini, not Agonini, have multiplied in 
what seem to be comparable habitats on the mountains. This 
difference can hardly be accounted for in simple ecological terms but 
is probably due to a complex combination of ecological, historical, and 
geographical factors. Over the world as a whole, there is a tendency 
for Agonini to be better represented in the tropics; Pterostichini, in 
the temperate zones. Also it is probable that Agonini, which are 
phylogenetically less diverse, are more recent in origin than Pterosti- 
chini and that they have dispersed more recently. It is therefore 
likely that Pterostichini are dominant in Australia partly because 
Australia is more temperate than tropical in climate and partly because 
Pterostichini reached Australia before Agonini did, and it is likely 
that Agonini are dominant in New Guinea partly because the climate 
there is fully tropical and partly because the carabid fauna of New 
Guinea is more recent in its origins than that of Australia, as I think 
it is. Add to this that the mountain carabid faunas of Australia and 
New Guinea have been derived independently, each from the lowland 
fauna adjacent to it, and not by dispersal along a connecting mountain 
chain, and we have an adequate and probably correct explanation of 
the great difference in composition of the carabid faunas on the 
mountains of Australia and New Guinea. 
As to direction of recent movements of Carabidae, movements of 
(winged) species have evidently occurred in both directions between 
Australia and New Guinea, although I cannot take space to give 
details now. Movements have apparently occurred also in both direc- 
tions between the tropical and subtropical forests of Australia. This 
is indicated by the relationship of the species now on the Eungella 
Range (p. 13), although I am not ready to give further details now. 
South of the tropics, patterns of distribution (Fig. 7) suggest 
withdrawal of cool temperate groups and southward spreading of 
tropical or subtropical groups. This is probably primarily an adjust- 
ment to recent warming of climate rather than an invasion of south 
temperate habitats by tropical Carabidae, although Pamborus , Tri- 
chosternus , and Notonomus have invaded N othofagus forest on high 
plateaus in New South Wales. 
