IV 
INTRODUCTION. By Dr. A. Seitz. 
coast of Australia and to Tasmania it has become impossible to draw a dividing line from the Indian region. 
The Papuan (Austro-Malayan) fauna, represented as an intergrade, is a subfauna of the Indian region and has 
nothing to do with the very primitive native Australian fauna. The latter is much more prevalent in the 
southern and western half of the Australian continent and in Tasmania than northwards. 
Whilst we still find among the Indian Heterocera affinities with Palearctic forms, in the north-western 
Himalayas, indeed, even a transitional region, there is no relationship at all between the primitive Australian 
fauna and that of the Palearctic Region. Australia also shows no sort of connection with South Africa and 
the southern part of South America. Certain resemblances — which, however, are very rare — have been pointed 
to as of zoogeographical importance, like the fact that ostriches are common to these regions, and have been 
regarded as indicating an earlier connection of the southern continents with one another; but as with the 
ostriches, it is doubtless a question in such cases of convergence. 
I. Division: Bombyces, Sphinges. 
In volumes II and VI it has already been emphasized that not much can be said in common con¬ 
cerning the two great groups known as Bombyces and Sphinges. They embrace the largest and also almost 
the smallest Macrolepidoptera; insignificant grey species and again brilliant, metallic day-fliers; some which, 
having the mouth-parts atrophied, can take no nourishment in the imago state, and others again which are 
markedly partial to flowers. As already mentioned, everything is included among the Bombyces which is 
neither butterfly, Sphinx, Noctuid nor Geometer. Phylogenetically the Bombyces are nearest to the Microlepi- 
doptera, to which the Psychid, Cossid, Hepialid, Aegeriid and Thyridid families show a close approximation. 
The Saturnids and Notodontids approach the Sphinges, the Uraniids and Callidulids the butterflies, whilst the 
Arctiids suggest a connection with the Noctuids, especially the Agaristids and Acronictids. 
Among the few families which are confined to the Indo-Australian Region we may first mention the 
Callidulidae. Only quite a few species of this family touch the Palearctic Region. Of the Nyctemerids, which 
likewise belong almost exclusively here, a few also occur in Africa. But there are also some subfamilies in 
which the majority of the species inhabit the Indo-Australian Region, and these Indian genera are furthest 
removed from the American members of the family. Thus we may call the Chalcosiines mainly oriental, and 
also the Cymbid and Hypsid genera; the latter and the Agaristidae also occur in Africa, although not in such 
large numbers. The other Heterocerous groups referable to the Bombyces and the Sphingidae are scattered 
over almost all the faunae. 
Finally, as regards the total number of species of Indo-Australian Bombyces, it possibly equals that 
of the American; that of the Ethiopian and Palearctic Regions it far surpasses. 
