Wll 
TM’RODUCTIOX. 
luinici'ically, but increase i>'reat]y in size and nnnil)er of transverse ridges. b)i', Chalmers 
INIitcliell lias lately sliown ('frans. Zool. 8 oc. vol. xvii. 1905, pp. 4G4-7) that the Sirenia 
and l’rol)()scidea rescmihle (uie another in the arrangement of tlie intestinal tract and 
that in neither group is there any trace of the Ungulate specialisation : it is also 
significant that he states that Ihjrax likewise approaches the Sirenia in this respect. 
In a former ]):i[)er (I’hil. 'J'rans. vol. 19C b(1903) p. IIG) it was stated that the possession 
of a non-deciduate zonary jdacenta was common to the two groups in question, but it 
has been pointed out by Messrs. Assheton and Stevens (Quart. Journ. Micr. Sci. vol. xlix. 
1905, ]). 1) that this is an error, and that, as a matter of fact, in the Proboscidea the 
|)lacenta is deciduate. At the same time, these writers show that in both groups 
the placenta, in addition to the short villi, also possesses a number of larger and longer 
\ irii, which deeply penetrate the maternal tissue and seem to be torn off at parturition. 
Although these points of similarity, taken separately, may be of no groat value, 
together they supply a very strong argument in favour of the close relationship of the 
two orders. 
All the Carnivora at present known from the Upper Eocene of the Fayilm belong 
to one family, the Ilyienodontida?, of the primitive group, the Creodonta. They are 
remarkable from the fact that in the four genera represented, viz. Sinopa, Apterodon, 
I’fcrodon, and lipcenodou, the molar teeth show four stages in the development of the 
cutting-blade and in the reduction of the talon and the postero-internal cusp. It 
seems highly probable that these animals entered Africa from the north, where 
Creodonts are found in the earlier Eocene deposits ; but at the same time the fact that 
the Zeuglodont Protoccdus from near the bottom of the Lower Mokattam beds, has a 
dentition which is practically that of a Creodont, clearly indicates its origin from 
members of that group, which may therefore have inhabited this region at a still 
earlier period. Since, however, Protoccdus is already fully adajhed for marine life, 
this is by no means certain, for it may have crossed from the northern side of the 
Nummulitic sea. Another argument for the existence of earlier Creodonts in 
the Egyptian region is that, since there is considerable probability that Africa was 
connected by a land-bridge with South America in late Cretaceous and possibly even 
at the beginning of the Tertiary period, their presence in Africa would account for 
the existence of the Sparassodonta in the Tertiaries of Patagonia. 
The Zeuglodonts of the Fayum, taken together with a species, Protoccdus atavus, 
recently described by Prof. E. Fraas ( 29 ) from the limestones of the Mokattam Hills, 
form a series showing a complete transition, so far at least as the dentition is concerned, 
