"Number 4, represented by three or four very fine specimens, is a very large leaf, measuring 13 cm. in length and 3½ cm. in width at the broadest point. It may be compared with Salix macrophylla, Heer,42 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.
"While it is manifestly impossible, on the basis of the above identifications, 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 resemblance to the present existing flora of Alaska it is likely to be much younger." [F. H. Knowlton.]
Very sincerely yours, LESTER F. WARD.
38 Mem. Mus. Comp. Zool., vol. VI, no. 2, 1878, p. 10, pl. i, figs. 18–21.
39 Flor. foss. Arct., vol. I, 1868, p. 102, pl. iv, figs. 11–13; pl. xlvii, fig. 11.
40 Proc. Nat. Mus., vol. V, 1882, p. 447.
41 loc. cit., pl. viii, fig. 6.
32 Tert. Fl. Helv., vol. II, 1856, p. 29, pl. lxvii, fig. 4.