384 ORTMANN— DISTRIBUTION OF DECAPODS [Aprils, 



ruption is a doable one, the Lemurian bridge between Madagascar 

 and India being destroyed and India becoming again disconnected 

 from the Sinic land. 



The southern part of Antillia (with Guiana) becomes united with 

 Archiplata. 



Archiplata becomes connected with Antarctica. 



Antarctica is cut off from Australia. 



This results in the following five isolated continental masses : 



I. Sino-Nearctic continent. Composed of the whole of North 

 Atnerica (including possibly the Scandi?iavian mass in Europe;, the 

 northern parts of Central America and of Eastern Asia (Sinic 

 land). 



Sino-Nearctica comes very near to what von Ihering has called 

 Archiboreas^ with the exception that Europe does not belong to it. 

 Von Ihering's Archiboreas is almost identical with the *' Holarctic 

 region,''^ only from the latter the ^^ Sonoran region^' (southern 

 North America) is excluded. 



II. Old Tertiary Africa. This mass nearly approaches to 

 present conditions, but still includes Madagascar and Arabia. 



III. The Indian Island. A very small part, hardly worth the 

 name of a continent, but here so-called in order to emphasize this 

 important stage in the development of southern Asia. 



IV. Australia, which closely resembles its present form. 



V. Archinotis and Archiplata^ together with the southern parts of 

 old Antillia (northern South America). This largely represents 

 present South America with the addition of the Antarctic land. If 

 we are to choose a name for it, we should like to propose 

 Neonotis, in allusion to its relation to the older (Upper Cretaceous) 

 Archinotis and the Neotropical continejit of recent times. 



d. Upper Tertiary. (See Fig. 8, p. 385.) 



The following are the most important changes : 



Sino Nearctica is greatly enlarged, and becomes connected with 

 the following parts: i. in the Old World, with the island o^ hidia^ 

 with Africa, with the Eurof^ean Archipelago, and with Scandinavia ; 

 2. the Nearctic part of Sino-Nearctica becomes connected, in the 

 region of the Istlimus of Panama, with Neonotis (South America). 



Miidagnscar is cut off from Africa. 



Antarctica becomes separated from South America. 



