CHILE 



643 



ica, the Navidad flora contains 3 species in common with that found in 

 the Loja basin of Ecuador, 2 species in common with that found in Co- 

 lombia, and 2 species in common with that described recently from Peru. 

 When compared, on the other hand, with the geographically much less 

 remote flora found in the Magellanian beds along the straits of that name 

 and on Tierra del Fuego, it is found to have nothing in common with the 

 latter except a single species of Flabellaria, about which Dusen expresses 

 the opinion that it could not have come from the Magellanian beds, and 

 in this Dusen appears to be perfectly justified. It appears that the 

 Navidad flora is younger than the floras known from farther south. 



Before discussing the age of the Navidad beds, I wish to refer to the 

 so-called Patagonian beds of southern Argentina, the marine fauna from 

 which has been admirably described by Ortmann.^^ This fauna has been 

 satisfactorily shown to be of lower Miocene age, and while the Australian 

 and New Zealand element is more pronounced than in the Navidad beds, 

 nevertheless the Patagonian has, out of a total fauna of 151 species, 34 

 that are identical with and 15 additional that are closely allied with 

 Navidad species. Ortmann quite rightly concludes that the Patagonian 

 is synchronous with at least a part of the series referred to the Navidad. 



In conformity with the conclusions of invertebrate paleontology as ex- 

 pressed by Stein mann, Moricke, Ortmann, and others, and from a con- 

 sideration of the flora found in these beds, I would confirm the lower 

 Miocene age of a part at least of what goes under the name of Navidad 

 ])eds and I would consider them as representing the Burdigalian stage 

 and possibly the older Aquitanian stage as Avell, since transgression was 

 continuous in Europe from the one to the other as it was also in the Canal 

 Zone. The presence of some of the mollusca of the Navidad beds in the 

 Magellanian Oligocene may indicate that a part of the former is still 

 older than Aquitanian, but this I greatly doubt, since the facts can be 

 explained by intermigrations of the forms better than by postulating con- 

 temporaneity. The facies of the Navidad flora appears to be slightly 

 older than the previously mentioned fossil floras from Colombia, Ecuador, 

 and Peru, and it may well fall within the Aquitanian, but it is surely not 

 so old as Eocene, as Steinmann and De Lapparent suggest, nor is it so 

 old as the Fagus flora of the Straits of Magellan and Tierra del Fuego, 

 which I have considered as Lower Oligocene in age. 



Windhausen^* has recently described tlie hitlierto unknown (wrongly 



"A. E. Ortmann: Tertiary Invertebrates. Princeton Exped. to Tataqonin vol 4 

 inol-lOOfl, pp. 45-.^32, pis. ll-.'?0. 



" A. Windliausen : The problem of the Cretaceous-Tertiary boundary In South America 

 and the stratigraphic position of the San Jorge formation in Patagonia. Am Jour Scl 

 (iv), vol. 45, 1918, pp. 1-53. 



