100 



DR. C. W. ANDREWS ON THE 



fact that these animals were very heavily built and probably semi -aquatic, so that 

 their spread into new areas may have been very slow and perhaps was checked by 

 barriers that would not Interfere with the Tetrabelodonts. 



The fact that no remains of Proboscideans, have been found in any pre-Miocene 

 deposit of Europe, Asia or North America shows clearly that the group cannot have 

 originated in any of those continents, but must have arisen on some adjacent land" 

 area, from which also several other families, appearing for the first time in the 

 European Miocene, may have been derived, and various speculations as to the position 

 of this land-area have been put forward. Among later writers the hypothesis that 

 the Ethiopian region was the centre of distribution of the Proboscidea has been 

 formulated must distinctly by Stkii i.in :;: and ()sn<)RX,t both of whom consider that not 

 only the Proboscidea, but also a number of other groups such as the Hyracoidea, the 

 ( M-ycteropodidre, the antelopes and the giraffes are of African origin; and to these 

 Forsyth Major} would add the Cercopithecidse. Osborn considers that migrations 

 from Africa into the Eurasian continent have occurred on several occasions, notably 

 towards the end of the Eocene, at the beginning of the Miocene and at the beginning 

 of the Pliocene. On this hypothesis it must have been during the early Miocene 

 immigration that the Proboscidea reached the northern region, probably along some 

 land connection established at the commencement of the great earth movements that 

 culminated in the formation of the Alpine mountain system. 



The accuracy of the hypothesis of an Ethiopian centre of distribution of the 

 Proboscidea has been fully demonstrated during the last two years by the discovery 

 of a number of primitive members of the sub-order in the Middle and Upper Eocene 

 beds of the Fayum district of Egypt, where they occur associated with remains of 

 other mammals, especially of early Hyracoidea, as well as of some remarkable reptiles. 

 The great interest of this discovery will be recognised when it is considered that in 

 the paper by Professor Osborn, above referred to, Africa is spoken of as " the dark 

 continent of palaeontology, for it has practically no fossil mammal history." The 

 material for at least the beginning of such a history is now available, and it is to be 

 hoped and expected that within the next few years much will be added to it. 



The Proboscidea so far collected from Egypt are: (I) From the Middle Eocene, 

 Ma ritlterium (three species) and Barytherium ; (2) from the Upper Eocene, Palceomas- 

 todon and perhaps Arsinoitherium.§ The presence in these beds of so considerable a 



* Stehlin, " Ueber die Geschichte des Suiden-Gebisses," II Theil ; ' Abh. d. Schweiz. Palaeont. Gesells- 

 chaft.,' vol. 27 (1900), p. 477, et seq. 



t OSBORN, " Correlation between Tertiary Mammal Horizons of North of Europe and America," ' Ann. 

 X.Y. Acad. Sci.,' vol. 13, pp. 1-72, 1900. 



I 'Geological Magazine,' Dec. 4, vol. 3 (1896), p. 436. 



§ [J ,l b T , 1903. Since this was written, remains of a species of Mceritherium have been found by 

 Mr. BEADNELL and myself in the Upper Eocene beds, where, however, they are very rare. On the other 

 hand, no trace of Pakeomasfodon has been found in the Middle Eocene.] 



