200 /. C. Russell— Expedition to Mount St. Elias. 



some forms of the living S. rosfraia, Richardson, with entii-e leaves. It is 

 clearly a willow, but closer identitu-ition must remain for more complete 

 material. 



" Number 3, represented by four or five sjiecimens, is broadly elliptical 

 in outline, and is also clearly a Salix. It is unlike any fossil form with 

 which I am familiar, but is very similar to the living S. nigricans, For., var. 

 rotundifoUa, and to certain forms of aS'. silesiaca, Willd. The nervation is 

 very distinctly preserved, and has all the characters of a w^illow leaf. 



" Number 4, represented by three or four very fine specimens, is a very 

 large leaf, measuring 13 cm. in length and 3] cm. in width at the broadest- 

 point. It maj^ be compai-ed with Sali.v macroptu/Uo, Heer,* but it cannot 

 be this species. It is also like some of the living forms of S. nigra, Marsh., 

 from which it differs in having perfectly entire margins. 



" AYhile it is manifestly imijossible, on the basis of the above identifica- 

 tions, to speak with confidence as to the age or formation containing these 

 leaves, it can hardly be older than the Miocene, and from its strong re- 

 semblance to the present existing flora of Alaska it is likely to be much 

 younger." [F. H. Knowlton.] 



Very sincei'ely yours, Lester F. Ward. 



*Tert. Fl. Helv., vol. II, ISoG, p. 29, pi. Ixvii, fig. 4. 



