NO. I DISTRIBUTION OF THE ONYCHOPHORA — CLARK 1 7 



peting forms which everywhere else have succeeded in extirpating it, 

 in one case by barriers of water, in the other by barriers of mountain 

 ranges. 



THE DISTRIBUTION OF THE PERIPATOPSID^ 

 The family Peripatopsidse includes fewer, but far more diverse, 

 types than the singularly homogeneous Peripatidse. It ranges from 

 New Britain, New Guinea, and Ceram (in the Moluccas) to Aus- 

 tralia, Tasmania, and New Zealand, and thence to southeastern and 

 southern Africa, and to Chile. 



The subfamily Peripatopsinse inhabits New Britain, New Guinea, 

 and Ceram, and also Cape Colony and Natal. At first sight this distri- 

 bution appears to be quite anomalous, but in reality it agrees perfectly 

 with what we know of the distribution of a number of other organ- 

 isms, confirming the evidence presented in other groups of a past 

 land connection between the Moluccas, New Guinea, and New Britain, 

 and southeastern Africa. 



The Peripatopsinse and the Eoperipatinse are not at present known 

 to occur together anywhere in the east, being separated by a line, 

 passing west of the Moluccas. 



This line, which separates the Peripatidse from the Peripatopsidse 

 as well as the Eoperipatinse from the Peripatoidinse, is the equivalent 

 of the famous Wallace's line, for it separates the Australasian from 

 the Indo-Malayan types. 



Unfortunately we cannot as yet, on the basis of the onychophores, 

 say what the exact location of this line is; we only know*that the 

 genus characteristic of New Britain and New Guinea (Paraperipatus) 

 occurs also on Ceram, and therefore the line must pass somewhere to 

 the westward of Ceram, between Ceram and Sumatra, where the 

 easternmost representative of the Peripatidse occurs. 



The distribution both of the Peripatidse and of the Peripatopsinse 

 confirms the presence in the distant past of a land mass extending 

 from the Malayan region westward and southwestward to central and 

 southern Africa ; and it is reasonable to suppose that the same land 

 mass, though possibly at different epochs, served for the migration of 

 both types, one passing over the more northern portion, the other 

 over the more southern. The Peripatidse passed over Africa into 

 America, but the more specialized Peripatopsinse, possibly later 

 arrivals, went no farther than Africa. 



In the Peripatidse the most specialized type is that in the Indo- 

 Malayan region, but in the Peripatopsinse we find the most specialized 



