( oxxx ) 



Ansti'jiliii anil to Nurtli Imlia ami tho Pacific Palaearctic Siiliroo'inn * : and couple 

 tiicse I'ucts with the absence of indigenous genera from the Archipelago (except 

 tlie Malayan (i'xjanfeopalixis) and the scarcity of peculiar species, it becomes 

 higlily ]irol)aMe that one and the same cause lies at the bottom of these 

 phenomena in distribution. Tlie simplest explanation would be to assume that 

 the Australian and Asiatic Continents were at an early period in the history of 

 the Siiliinijuhic at least as closely connected as they are now, the connection 

 allowing of the Asiatic fauna extending into Australia, and that later the inter- 

 jacent district became so far submerged that the fauna was practically destroyed. 

 With the separation of Asia and Australia by a wide gap, the condition for 

 the evolution of special genera and species was given in Australia. The reason 

 for the seven endemic genera of tropical Australia not having migrated over the 

 Pajman Islands may be purely biological ; or it is possible that at least two of 

 them {Lrucomonia and TetracJiron') really do occnr outside Australia, but liave 

 not yet been found. 



The Indo-Malayan Subregion has twice as many species of Sphingidae as 

 the Papuan Subregion, there occurring nearly 19U species, of which loO-odd do 

 not extend into the Papuan countries. The cause of tlie contrast is easily 

 perceptible. Papuasia is isolated from all Continents except Asia. Its entire 

 Sphingid poi)ulation is Indian in extraction, perhaps with the exception of 

 Coenotes, which has closer affinities to the Neotropical ISeogene. Since the 

 greater proportion of the Spliiiu/idae are swift-flying and of wide distribution, 

 and as a good many exist under adverse climatical conditions, and hence prove 

 themselves to be remarkably adaptive, it ap])ears to us to follow that the 

 Sphingid fauna of Australia would contain a good mixture of South American 

 and African elements, if there had ever, within the history of Sphingid'te, existed 

 an Antarctic (continent connecting these countries with one another, and suitable 

 for the existence of Hawk Moths. India and the neighbouring tropical districts 

 of Asia, on the other hand, have had an influx from the North and West, and, 

 being mountainous, offered at the same time the necessary conditions of life for 

 the maintenance of a great variety of species. It is especially the North East 

 of India, and most likely Burma and (Jhina — both of which are very imperfectly 

 explored — that harbour the largest number of Spliiiu/idac. South and West 

 India are much poorer in Sphiiigir/ae, as is indeed the case with nearly all 

 groups of Lejiidojitera. Though tlic absence of very many of the Himalayan 

 species and genera from Ceylon and South India is compensated for to a certain 

 degree by the appearance of some forms which do not extend to Sikhim, Assam, 

 and Burma, we emphasise that the Western Peninsula and Ceylon have very 

 few species of their own and no genus ])eculiar to themselves, the difierences 

 being chiefly subspecific. The siguiflcance of this fact will be understood if we 

 add that a few Palaearctic and African species reach into the Western Peninsula 

 or the adjacent North Western districts {Mdcroglossxm sti-UatarHm, IhUcplnbi 



* The Australi.an PupU'io Ifostlwiics, wliich has its nearest relatives in Asia and Europe, may be 

 mcniioncd in this connection. 



