ANNIVERSAKY ADDRESS OP THE PRESIDENT. IO3 



V-shaped molars that is found out of Africa and Madagascar is 

 that of the Solenodontidce of the West Indies. These insectivores 

 are some of the most lowly organized of all placental mammals, 

 and may be more ancient than other members of the subclass. 

 Amongst the rodents, another placental order of low organization, 

 one family, Octodontidce, is restricted to Africa and South America. 



Of course some of the instances mentioned may be explicable by 

 the former existence of allied forms in Europe and Forth America. 

 But it is very difficult to conceive that so many cases of relationship 

 between the lower vertebrata of Africa and South America can be 

 explained in this manner. The biological evidence of a former land- 

 connexion between South America and Africa is much stronger 

 than that in favour of a belt of land between Africa, Madagascar, 

 and India, although the latter is supported by geological data. It 

 is probable that the land-barrier across the South Atlantic, if that 

 was the form of union, lasted to a later geological epoch than that 

 across the Indian Ocean. 



The direction in which the communication between South America 

 and Africa lay is very difficult to indicate. The relationship is 

 chiefly shown by tropical forms, but these may have migrated far 

 to the southward during warm periods. It is highly probable that 

 the southern extremity of South America at one time extended to 

 the eastward, beyond South Georgia, and land may have united 

 this tract with South Africa ; but there is nothing known of the 

 sea-bottom to indicate the probability of union in this direction. 



The only ancient palseontological evidence, so far as I am aware, 

 is that pointed out by Neumayr in the paper already referred to *. 

 He infers land-connexion between Africa and South America in the 

 Jurassic and Lower Cretaceous periods from (1) the absence of 

 Jurassic marine beds on the western coast of Africa and on the 

 eastern coast of South America ; (2) the evidence of ancient land in 

 the Cape Verde Islands and St. Paul's ; (3) the fact that theNeoco- 

 mian Uitenhage fauna of the Cape of Good Hope differs entirely 

 from the European, whilst the Jurassic fauna of western South 

 America does not. The first two grounds appear insufficient, even if 

 the facts were fully admitted ; but the third has more force and 

 would appear to indicate a westward or southward prolongation of 

 the South- African land so as to meet a corresponding south-eastward 

 extension of South America. 



It must not be forgotten that the area around the South Pole as 

 far north as about 60° of .south latitude, so far as is known, is occu- 



^ Log. cit.-p. 132. 



VOL. XLVI. 7l 



