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A Tertiary Ginkgo from Patagonia 

 Edward \V. Berry 



With the discovery to which this note is devoted the ( iinkgo 

 has now been recorded from all of the continental areas. Its 

 most extensive range appears to have been attained in the mid- 

 dle Mesozoic. Tertiary species have heretofore been unknown 

 outside the Northern Hemisphere, where they have survived in 

 western Europe as late as the Pliocene and in Asia and North 

 America as late as the Miocene. The latest Arctic occurrences I 

 regard as older Tertiary. 



In a collection of fossil plants from northern Patagonia which 

 reached me last spring are a considerable number of leaves of a 

 new species of Ginkgo. This material comes from Rio Pichileufu 

 about 30 miles east of Lago Nahuel Huapi in Rio Negro Terri- 

 tory, the locality being about 41° 10' south latitude and 70° 52' 

 west longitude. The matrix is a fine grained andestic tuff and 

 the preservation is excellent. 



This species may be named Ginkgo patagonica and de- 

 scribed as follows: Leaves variable in size, long petiolate, fan 

 shaped with a cuneate base, divided by a sharp median sinus 

 which extends f s to f s of the distance to the base into 2 primary 

 segments. Each of these is invariably divided by a sharp but 

 less deep sinus into 2 equal round-tipped segments. In about 

 half the specimens this represents the maximum dissection. In 

 the remainder the outer segments are bisected to a greater or 

 less degree. The leaf substance is fairly coriaceous and the veins 

 are largely immersed. The veins are stout and the venation is 

 typical of the genus, except the outer marginals are not so 

 prominently differentiated as is usual in the existing Ginkgo 

 biloba. 



The petiole is stout and striated, slightly expanded at the 

 base and measures 4 centimeters in length in the only complete 

 specimen, in which the lamina is 5 centimeters long and about 

 the same in maximum width. The cuticles are preserved in most 

 of the specimens but had been allowed to dry and slack for sev- 

 eral years before coming into my hands, and hence it has been 

 impossible to make sufficiently good cuticular preparations for 

 photographing-. The cell outlines are quadrangular more often 



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