84 



The leaves described as Liriodendron honsyiiensis from Japan 

 are definitely different from those ascribed to Liriodendron hesperia 

 from Washington, but because of the sparseness of material it is 

 impossible to know their respective limits of variation and for the 

 same reason it cannot be determined whether the Japanese fossil 

 leaves should be regarded as more closely related to the existing 

 Chinese tree, and the same remark applies to the degree of affinity 

 of Liriodendron hesperia as between the existing species of China 

 and that of the southeastern United States. There is some evidence 

 in the Mesophytic floras of our Pacific slope Miocene of a closer 

 relationship with existing eastern Asiatic floras than with existing 

 southeastern American floras. This evidence is highly suggestive 

 but from the nature of the material cannot be susceptible of proof. 



This evidence is of two sorts, (1) where the genus survives in 

 both regions the fossil form is more like a modern Asiatic than a 

 modern American species. Examples are Castanea orienfalis Chaney 

 and Castanea crenata Sieb. and Zucc. of Japan ; Styrax n.sp. Berry 

 and Styrax japonicum Sieb. and Zucc. of Japan; Betula largei 

 Knowlton and Betula luminifera Winkler ; Rhus merrilli Chaney 

 and Rhus sylvestris Sieb. and Zucc. ; Malus idahoensis Brown and 

 Mains prunijolia Willd. ; Fraxinus idahoensis Brown and Fraxi- 

 nus inopinata Ligelsh. and platypoda Oliver of eastern Asia. (2) 

 where the genus is no longer represented in America. Examples 

 are Ailanthus americana Ckl. and Ailanthus gland-ulosus Desf. of 

 China, Paliurus hesperiiis Berry and Palinrus orientalis; Cercido- 

 phylhim crenatum (Unger) Brown and Cercidophyllum japonicum 

 Sieb. and Zucc. ; Keteleeria heterophylloides (Berry) Brown and 

 Keteleeria davidiana Beissner ; Dipteronia americana Brown and 

 Dipteronia sinensis Oliver; Trapa americana Knowlton and the 

 Asiatic Trapa bicornis L. and bispinosa Roxburg. 



Literature Cited 



1. Berry, Tree Ancestors, pp. 171-180, 1933. 



2. Chaney, R. W. Walker Mus. Cont. vol. 2, No. 5, p. 173, pi. 14, fig. 4, 1920. 



3. Berry, E. W. Canada Geol. Surv. Bull. 42, p. 110, 1926. 



4. Berry, E. W. U. S. Geol. Surv. Prof. Paper 154, p. 249, pi. 51, figs. 2, 3, 



1929. 



5. Brown, R. W. Journ. Paleont. vol. 9, p. 577, pi. 69, figs. 14, 15, 1935. 



6. Endo, S. Proc. Imp. Acad. vol. 10, No. 9, pp. 590-593, figs. 1, 2, 1934. 



7. Endo, S. Yabe Jubilee Publ., p. 345, pi. 23, fig. 12, 1939. 



Johns Hopkins University. 



