550 DISCUSSION ON RESULTS RECORDED 



from the one continent to the other by the north. We know only 

 a very few tetrapod vertebrates, but those known from Brazil are 

 strikingly similar to those that occur in South Africa. A few 

 5'ears ago I described a new specialised Mesosauiian, JVoieosaurus, 

 which differed from Mesoscatrus in having the 5th digit of the 

 hind foot very slender and provided with six phalanges. Shortly 

 afterwards the same peculiar type turned up in Brazil. Meso- 

 saarus and Noteosaurus were small freshwater- inhabiting reptiles 

 which might at suitable times have passed from one river-basin 

 to another like newts or frogs, but which could never have lived 

 at sea. It is difficult to believe that they could have jDassed 

 round either the Atlantic or Pacific by the north sufficiently 

 cjuickly, even if there were no other apparently insuperable 

 difficulties, to have appeared practically contemporaneously in 

 South Africa and South America. 



We know that in Lower Devonian times the littoral fauna of 

 South Africa was practically the same as in the Falkland Islands. , 

 We can therefore be quite certain that the oceans are not per- 

 manent, and that what is now the South Atlantic had land 

 stretching aci'oss it in Devonian times. We may be equally sure 

 that much of the South Atlantic was land in Permian times. 

 There is also good reason to believe that the land-conditions con- 

 tinued into the Triassic and Jurassic. If the elevated conditions 

 continued into the Cretaceous, of which there is some direct 

 evidence, we could have a sufficient mingling of piimitive forms 

 of life to probably account for all the known peculiarities of 

 distribution. 



When in New York recently I had numerous discussions on 

 the subject with Dr. Matthew, but while I am willing to admit 

 that the evidence is rather against any Tertiary land-connection 

 uidess it be a Lower Eocene one, I have always felt strongly that 

 there must have been a Cretaceous connection. The facts which 

 Mr. Tate Regan has laid before us are, I think, quite inexplicable 

 on any other hypothesis. 



Mr. W. L. ScLATER, M.A., F.Z.S., said that he agreed with the 

 last speaker. Dr. Broom, that it was quite possible to postulate 

 the existence of a land-bridge between South America and South 

 Africa in Secondary times, but that he believed that the present 

 distribution of the ocean-beds and great land-masses had been 

 continuous since the commencement of the Tertiary epoch, and 

 that, so far as he could see, njre of the difficult problems of the 

 distribution of the higher groups, i. e. Mammals and _ Birds, 

 required for their solution the hypothetical existence of land- 

 bridges across the present deeper ocean-beds. He reminded his 

 hearers that the comparatively short duration in time of the 

 Tertiary epoch as compared with the Secondary and the Secondary 

 as compared with the Primary, was not always taken into con- 

 sideration in the discussion of these problems from a zoological 

 standpoint. 



