Introduction. 
The plant-bearing beds dealt with in this paper were studied by the writer 
during the Swedish Expedition to South America in 1907—1909 under the direction 
of Dr. C. SKOTTSBERG. Most of the fossil plants collected during this expedition in 
Patagonia and Tierra del Fuego are of Upper Cretaceous and Tertiary age. In the 
present paper only the older floras will be treated, i. e. those from the time before 
the appearance of the dicotyledons. These older floras are not only more easily 
studied than the younger ones — which are composed mainly of dicotyledons and 
require a detailed comparison with the present vegetation both of South America 
and other continents — but also, on the whole, of greater interest, because their 
existence in this region was not hitherto known. "The fossil plants described in this 
paper, as well as all the palaeobotanical collections of our expedition, are in the 
Palaeobotanical Department of the State Museum of Natural History at Stockholm. 
To the Director of this department, Professor A. G. NATHORST, I desire to render 
my sincere thanks for much helpful assistance in my work. 
From the whole of that part of South America which lies south of the latitude 
of Buenos Aires there have only been described some few and poor plant-remains 
belonging to a flora that is older than the first appearance of the dicotyledons. 
These fossils, which have been described by Kurtz (1901), were found by ROTH 
(1901) at Piedra Pintada on the nothern border of Patagonia, in beds with marine 
fossils considered to be of Liassic age. KURTzZ mentions the following species: Asple- 
nites macrocarpus FEISTM., Thinnfeldia sp., Dictyophyllum sp., Otozamites Ameghinoi 
Kurtz, O. Bunburianus ZiGNO, O. Rothianus Kurtz, O. Barthianus KURTzZ, Brachy- 
phyllum sp. The flora is compared by Kurtz with the Rajmahal Flora of the Upper 
Gondwanas of India. 
South of Piedra Pintada there were known, until recently, only dicotyledonous 
floras, of which the most important as well as the oldest is that of Cerro Guido in 
south-western Patagonia. This flora, which was discovered by HAUTHAL, has been 
described by KurrTz (1899) and compared by him with the Cenomanian Dakota 
