MATTHEW, PATAGONIA AND PAMPAS CEN0Z01C 
151 
Dr. Ameghino in his correlation places greater weight upon the first, 
Dr. Roth upon the second means. European and North American pale¬ 
ontologists have in general been indisposed to accept the results of either 
of these methods at their face value, unless supported by (1) known strati¬ 
graphic relations to marine faunae, or by (2) direct comparison of some nearly 
related types in the stages to be correlated. 
The question is of necessity a difficult one, and it is doubtful whether it 
can be securely settled until we know more of the origin and direction of 
migration of the various components of the faunae involved. If, as is the 
practically unanimous opinion of European and North American writers, 
the vast majority of the Tertiary and modern mammals originated in the 
North, it is obvious that the geological age of equivalent stages in most phyla 
will be later in Patagonia than in the northern world. If, as Dr. Ameghino 
believes, Patagonia was the center of dispersal of the majority of Tertiary 
and modern mammals, the reverse will be true. 
In the first case the Patagonian faunae will be more recent than they 
seem; in the second case they will be older. And it should be observed that 
the same will hold true of the marine faunae, although perhaps the divergence 
between actual and apparent age will not be so wide. If the majority of 
groups of marine vertebrata and invertebrata originated along the coasts 
or in the seas of the northern hemisphere, then the real age of the marine 
faunae of the southern seas and coasts will be less than their apparent age; 
they will be, like the land faunae, unprogressive and archaic in comparison 
with their northern contemporaries. 
We may review briefly the principal data which Dr. Roth brings forward 
in support of his correlations: 
I. The Notostylops Fauna. 
1. Roth confirms positively the assertion of Ameghino that this mamma¬ 
lian fauna is unquestionably associated with Dinosaurs. This means either 
that it is of Cretaceous age, or that Dinosaurs survived in South America 
into the Eocene epoch. But the beds in which the Notostylops fauna occurs 
are, according to R,oth, quite certainly of identical age with the marine 
Roca beds, which are admitted by Wilckens to be Cretaceous. Unless 
therefore we suppose, as the reviewer has intimated above, that the marine 
faunae of the southern coast may be more recent than homotaxial marine 
faunae in the northern world, we must admit, apparently, that this fauna is 
of pre-Tertiary age. 
2. He denies the presence of rodents in this fauna, but it includes 
armadillos “of which some are scarcely distinguishable from those living 
