13 



This South American ( '.inkgo is associated with an abundant 

 arborescent flora which is chiefly dicotyledonous, but which con- 

 tains several ferns, an abundant cycad belonging to the genus 

 Zamia, and conifers representing the genera Araucaria, litz- 

 roya, Libocedrus and Podocarpus. There are also a few fruits 

 and seeds, cyprinodont fish scales and insect remains; the latter 

 chiefly beetle elytra. 



The picture presented by this flora is in striking contrast to 

 the present day conditions in this region, which is now a wind- 

 blown treeless pampa with an annual precipitation of less than 

 20 centimeters. The ecological picture of the Miocene conditions 

 has not yet been fully worked out since the identification of 

 some of the elements, especially among the dicotyledons, is un- 

 usually difficult. 



One is tempted to say something of the ancestry of the 

 (iinkgo but this fascinating subject has been discussed repeat- 

 edly in recent years. One thing the present discovery empha- 

 sizes is the paucity of our knowledge of Cretaceous and Tertiary 

 floras in South America and that this is due, not so much to 

 their lack, as it is to the pitifully small amount of geological ex- 

 ploration. 



The Johns Hopkins University, 

 Baltimore, Maryland 



1 Halle, T. G. Kgl. Svenska Vetens-Akad. Handl. Bd. 51, No. 3, p. 37, pi. 

 4, figs. 23-30; pi. 5, figs. 1-4, 5 (?), 6 (?), 1913. 



