230 Annals of the South African Museum. 



and that of the Uitenhage Series. It is probable, however, that this 

 contrast may be due to a difference of facies, and in any case the 

 argument derivable from it is greatly weakened, if not rendered 

 valueless, by the relation seen to exist between the Uitenhage 

 molluscan assemblage and that of the more truly comparable faunas 

 in East Africa and Cutch. There are other facts also which are 

 known to cast doubt upon the existence of an effective barrier to 

 migration between the equatorial and southern waters to the east of 

 the African continent, in Cretaceous times. 



Neumayr laid great stress upon the occurrence of Belemnites 

 africanus in the Uitenhage Series in support of his theory of the 

 distribution of cephalopods according to climatic zones. He found 

 this form to belong to a group which, though occurring in the colder 

 waters of the northern hemisphere, appeared to have no represen- 

 tatives in the warmer equatorial regions. While the known distribu- 

 tion of Holcostephanus (sensu stricto) might at first thought be 

 considered to support in a similar manner the broad principle laid 

 down by Neumayr, it would certainly not be justifiable to attach any 

 such significance to the facts. Our knowledge is as yet very 

 incomplete, but a body of evidence relating to the distribution of 

 fossil Cephalopoda has now been accumulated, which casts the 

 strongest possible doubts upon the soundness of Neumayr's theory. 

 Hence it will be well to exercise the greatest caution in the attempt 

 to estimate the significance of the Uitenhage Cephalopoda in any 

 general question of distribution. The apparent absence of identical 

 or closely related forms from the Neocornian rocks of German East 

 Africa and of Cutch is in all probability owing either to our imperfect 

 acquaintance with the fossil faunas in these districts, or to conditions 

 of a local nature which may really have determined the absence of 

 such forms, in manner not unknown among the Cephalopoda of 

 various geological horizons within restricted areas in Europe. 



