THE AMERICAN NA TURALIST. [Vol. XXXVII. 



sions, which seem well supported, at any rate they are better 

 supported than the previous very general theories concerning these 

 parts. We may summarize them here as follows. 



1. We are to abandon Neumayr's theory of a large Jurassic Sino- 

 -Vustralian continent. Sufficient evidence has been brc ^1 t fo a d 

 to show that at least a large part of the present Indo-Australian 

 region was covered by sea in Jurassic times, and, moreover, that this 

 sea was by no means a shallow one. 



2. Zoological evidence supports the view of a continental connec- 

 tion of Asia and Australia during Cretaceous times. As to the size 

 and shape of this connection we possess hardly any indications : we 

 know that certain parts of the Archipelago were land during this 

 period, while marine deposits are known from other parts. 



3. During the Cretaceous, and pre-eminently so during the Terti- 

 ary, this region was characterized by frequent changes, but during 

 all these times it was a region if not of continental character, certainly 

 of that of a shallow sea with many islands. 



4. Wallace's line, a depression between Borneo and Celebes, and 

 said to be continued between Bali and Lombok, does not exist as a 

 zoogeographical boundary between Asia and Australia. Between 

 Bali and Lombok, it does not exist at all, the sea being very shallow 

 there. There is indeed a depression between Borneo and Celebes, 

 but this does not separate Asiatic and Australian faunal development 

 Celebes possessing Asiatic elements in a high percentage. Never- 

 theless, Wallace's line holds good for a separation of Celebes from 



fauna not from Borneo, but from the Philippine islands. 



5. The three larger Sunda islands (Sumatra, Java, Borneo) were 

 connected with one another and with the Asiatic continent in Plio- 

 cene times. The separation of these islands was not contemporane- 



6. Borneo was also united, at about the same time, with the 

 Philippine islands and South China. 



7. The smaller Sunda islands (Bali, Lombok, Sumbawa, Flores) 



ental, and in part Australian. The Australian elements possibly 



and, no doubt, once was part of this continent. 



8. Celebes was always separated from Borneo (beginning in the 

 Miocene), but it was connected with the Philippine islands on the 

 one side, and with Java and the smaller Sunda islands (Flores) on 



