BRANNEK : THE STONE KEEFS OF BRAZIL. 25 



Bahia, Alagoas, Pernambuco, Parahyba do j^orte, and Rio Grande do 

 Norte, but those already mentioned are enough to show beyond question 

 that the coloring is an accident without any evident relation to the age 

 of the beds.^ 



Tlie Tertiary beds of the Amazonas. — Fossils supposed to be of Ter- 

 tiary age have been described from the upper Amazon region, but the 

 age of the beds referred to seems never to have been determined with 

 certainty, though they are evidently not older than the Tertiary. As 

 long ago as 1854 Foetterle spoke of the lignite beds of 19a, Tabatinga, 

 Loreto, and Pebas on the Maraiion, which he supposed were of Tertiary 

 age.2 



Orton found at Pebas near the southern boundary of Ecuador fossils 

 which Gabb says " indicate a marine or perhaps rather a brackish water 

 fauna. There is not sufficient material to warrant an opinion as to the 

 geological age of the deposit," but he thinks they " point to a very recent 

 era." ^ 



Later Mr. Hauxwell made a larger collection at Pebas and at Pichua 

 thirty miles below Pebas. This collection was described by Conrad, who 

 is doubtful about the age of the beds.* He says that the fauna " may 

 have lived in either fresh or brackish water, but it certainly is not of 

 marine origin." The opinions of both Gabb and Conrad show that the 

 statement of Orton to the effect that these shells " may be Miocene " * 

 was premature. About the time that Conrad published his article there 

 appeared one by Woodward upon a collection from the same region.® 

 The author of that paper seems to take it for granted that Orton's 

 opinion of the age of the beds was correct, and says nothing of any 

 reason for referring them to the Tertiary. 



In 1872 Hartt published an ai'ticle upon the so-called Tertiary basin 

 of the Maraiion, but he never visited the region he was writing about, 

 and based what he said upon the papers of Orton, Gabb, and Woodward, 



1 J. C. Branner. The oil-bearing shales of the coast of Brazil. Trans. Amer. 

 Inst. Min. Engs., XXX., p. 5-37-554. 



2 Franz Foetterle. Die geologische Uebersichtskarte des mittleren Theiles von 

 Sud Amerika. p. 20-21. Wien, 1854. 



8 W. M. Gabb. Descriptions of fossils from the clay deposits of the Upper 

 Amazon. Amer. Journ. Conchology, 1868, IV., p. 197. 



* T. A. Conrad. Description of new fossil shells of the Upper Amazon. Amer. 

 Journ. Conchology, 1871, VI., p. 192. 



'•> James Orton. The glacial deposits of the valley of the Amazons. Geol. Mag. 

 1870, VII., p. 540. 



6 H. W. Woodward. The Tertiary shells of the Amazons valley. Annals Mag- 

 azine Natural History, ser. 4, Jan. and Feb., 1871, VII., p. 59-64, 101-109. 



