AMEGHINO'S SECTION II 



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 beefs 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, 



