Over a South Atlantic Continent 445 



Zealand, Campbell Islands, etc" it favors the possibility of 

 the persistence of at least considerable stretches of a 

 southern continent, till comparatively recent geologic time. 



But in the past twenty years it can well be said that 

 the need for a wide southern continent, has been increasing- 

 ly insisted on and accepted, as plant and animal choro- 

 graphers have compared their fast accumulating data. Thus 

 von Ihering, Ortmann, Gaudry, Geoffry Smith, Chilton, 

 Ancey, Hedley, Dusen, Skottsberg, and others have all 

 accepted such, though in some cases with caution or in 

 modified form from that of Forbes, as is true specially for 

 Hedley. As before stated, (p. 434) Forbes has advocated 

 a central Antarctic landmass, and in doing so writes: "If 

 the Antarctic sea-floor were elevated to a height not ex- 

 ceeding 2000 fathoms, the exposed land would form ap- 

 proximately the continent which I think, the evidence ad- 

 duced in this paper seems to demand; practically none of 

 that area is now below what Dr. Mill in his valuable "Realm 

 of Nature" terms the line of mean sphere level." 



Hedley considered (272:278) that a strip passing 

 across the Antarctic circle and joining S. America with the 

 N. Zealand area would suffice. Ortmann accepted the joint 

 view of Ruetimayer and Hutton that a southern continent 

 stretched across the S. Atlantis and Indian Oceans, but 

 modified according to Hedley's plan. So he writes: {2'/^:- 

 324)" we accept the first theory of Ruetimayer and Hutton, 

 with the restrictions put upon it by Hedley." 



Such a position as that of Hedley and Ortmann is now 

 rendered more likely, seeing that Antarctic discovery of 

 the past fifteen years by several of the national expeditions 

 has clearly shown that mild conditions existed during Ter- 

 tiary times over the whole or certainly a large part of 

 "Antarctica." The fossil flora alone definitely established 

 this. 



In connection however with our present study of fish- 

 distribution, as determined by past geographic and geologic 

 changes, the possible origin and distribution of the Mar- 

 supialia deserves attention. It is now generally conceded 

 that the most primitive of the three sub-groups of that 

 family is the Polyprotodonta. This includes the Opossums 



