VI CREODONTA AND MODERN MAMMALS 20 
primary division, proposed to be called Paratheria, is that of the 
Edentates. Probably the group so called should really be 
divided into the Edentata and the Effodientia, the latter con- 
taining the Old World forms. Whether or not it be ultimately 
shown that the Ganodonta are ancestral Edentates (sensu strictior7), 
the connexion of the group with others is not at present plain. 
The same is the case with the extensive order of Rodents. It 
is true that the extinct order of the Tillodontia shows certain 
Rodent-like characters on the one hand, and likenesses to Ungulates 
on the other. Certain likenesses shown by such apparently 
diverse animals as the Rabbit and the Elephant used to be 
insisted upon by Professor Huxley. For the present, however, the 
Rodents must remain as an isolated group with only very 
dubious affinities to others. The remaining groups of existing 
mammals are easier to connect. At first the differences between 
a Cat and a Horse seem to be quite as wide as those which 
separate any two of the higher Eutherian orders. But it seems 
to become clearer and clearer, as palaeontological investigation 
proceeds, that the bulk of the Ungulate and the Carnivorous, 
Insectivorous, and perhaps Lemuroid stocks converge into the 
early Eocene Creodonta. From the Lemuroid branch the higher 
Primates can be derived. The only “ Ungulates” which cannot 
be fitted in with some reasonable probability is the group of the 
Proboscidea. But of the early forms of this division we have at 
present no knowledge. 
