AMEGHINO'S SECTION 11 
interval that the Casamayor, the Deseado and _ possibly 
other beds were deposited on the continent. I have gone 
over Ortmann’s argument, and studied a large collection 
of Patagonian fossils, both vertebrate and invertebrate, 
of my own; and while there are some places where we would 
like further data, I can come to no other conclusion but 
that these Patagonian beds are Lower Miocene, the exact 
relationship with beds in North America and Europe, being 
as yet not definitely settled, nor will this be possible until 
a study of the migrations of the elements of the Patagonian 
fauna has been made. 
As to the beds underlying the Patagonian, I am sure that 
a considerable study of the marine series is still requisite 
to determine the relationships of the beds in different parts 
of Argentine, and their relative positions as compared with 
beds in other countries. Ameghino appended to his paper 
on the Formations Sedementaires a section of the strata 
exposed on the coast of Patagonia from Rio Negro to Cape 
Virgenes, on which from above Punta Atlas south to below 
Pico Salamanca, the Casamayor (=Notostylops) beds 
fill the interval from the Salamanca formation up to the 
Patagonian. On the strength of this map I followed these 
beds the whole distance looking for vertebrate fossils of 
Casamayor age. Nowhere did we find a Casamayor fossil. 
Instead at several points we did find marine fossils. I 
can not but feel that these beds are plotted as Casamayor, 
because of their resemblence in color and general texture 
to the beds carrying the Notostylops fauna at Casamayor. 
Of several sections of these beds I pick out two as typical, 
and also because they are near the locality which we worked 
for the Deseado fauna. On the map they are indicated 
as A and B. The former passes through a bed of green 
sands which is, I think, the locality indicated as his north- 
ern locality for the Pyrotherium fauna. 
From Punta Atlas to Pico Salamanca, Ameghino plots 
at or just below sea level a bed known as the Salamanca, 
