46 Windhausen — The Cretaceous-Tertiary 



gonia already appears in the Liassic of Chile 110 and must 

 be regarded as a persistent form of this province. Con- 

 sequently the appearance of Trigonia is not surprising. 

 As to the character of the fishes referred to by Ame- 

 ghino 111 it may be considered as especially interesting 

 that v. Ihering 112 points out the slight value of fish 

 remains for the decision of stratigraphic problems. He 

 recalls that G. de Alessandri 113 on the basis of fish 

 remains assigned an Eocene age to the Parana or Entre 

 Rios-Formation, whereas there can be no doubt at all 

 about the Later Tertiary age of this formation. On the 

 other hand, I found in the Roca-Beds near General Roca 

 a tooth of Odontaspis cuspidata Ag., a fish of the Euro- 

 pean Eocene. Therefore it seems to me better to omit 

 entirely the fish elements. 



According to v. Ihering, 114 a general Antarctic fauna 

 spread at the beginning of the Tertiary from New Zea- 

 land to Chile and Patagonia and had as its most charac- 

 teristic elements the genera Struthiolaria, Malletia and 

 Lahillia. The former two of these are represented in 

 the San Jorge-fauna, and the genus Lahillia may likely 

 be found in the future, when collecting work will be more 

 extensive. From the elements that have been indicated 

 by v. Ihering as most characteristic parts of this fauna, 

 the following genera (more than the half of the whole 

 list) are also represented in the San Jorge-fauna: 



Scalaria Mytilus 



Calyptraea Venericardia 



Turritella Phacoides 



Struthiolaria Cardium 



Bulla Panopaea 



Cucullaea Corbula 



Area Lima 



Ostrea Nucula 

 Myochlamys 



Wilckens, 115 discussing this statement, expressed the 



110 W. Morieke, Versteinerungen des Lias und Unteroolith von Chile. 

 N. Jahrb. f. Min., Beil.-Bd., 9, 1894. 



111 Les formations sedimentaires, p. 70. 



112 Die Conchylien der patagonischen Formation, N. Jahrb. Min., 2, p. 42, 

 1899. — See also Ameghino, Mammiferes cretaces de 1 'Argentine, Bol. Inst. 

 Geografieo Argentino, vol. 18, p. 115 of the abstract. 



"* Bicerche sui pesci f ossili di Parana, Atti B. Aecademia Scienze, Torino, 

 vol. 31, 1896. 



114 Les mollusques fossiles etc., p. 498. 



110 Die Mollusken der Antarktischen Tertiarf ormation, Wissenschaf tl. 

 Erg. der Sehwedischen Siidpolar-Expedition 1901-1903, 3, Lief. 13, p. 39, 

 Stockholm, 1911. 



