PLATE 30, FIGURE 3; PLATE 31, FIGURE 3; PLATE 32, FIGURES 2, 3
"Fagus n. sp." Hollick, Summary Kept. (loc. cit.), p. 134.
These leaves are very similar in general appearance to those of the existing North American beech, Fagus grandifolia Ehrhart, although our specimens are larger in size than the average of the leaves of the species mentioned, a typical, rather large leaf of which, collected in The New York Botanical Garden, is represented by FIGURE 2, PLATE 44. Fagus grandifolia (=F. ferruginea Aiton and F. americana Sweet), mostly represented by nuts and husks,15 has been identified in many of the American collections of Pleistocene plants; and well-preserved specimens of leaves, as well as a husk, were described and figured by Berry16 from the Pleistocene of North Carolina, under the synonym Fagus americana. These leaves, as figured, show a close resemblance to our specimens, and also to a fragmentary specimen from the Pleistocene of Maryland depicted by the writer17 and described as "Fagus sp.?" Whether or not these specimens, as well as ours, should all be referred to the existing species may best be regarded merely as a matter of individual opinion. It may, however, be pertinent here to call attention to the fact that almost equally satisfactory comparisons may be made with certain Tertiary species, such as Fagus deucalionis Unger18 of the Old World; F. Antipofii Abich and M. macrophylla Unger, as depicted by Heer19 from the Miocene of Alaska, and by Lesquereux from the Miocene of California; and F. sylvatica fossilis Laurent and Marty,21 from the Pliocene of the Netherlands, etc.
In general it may be said that the specimens from the Saint Eugene silts are most nearly comparable in size with leaves of Fagus of recognized Miocene and Pliocene age, and that in other surficial features they are closely similar to the existing F. grandifolia. Satisfactory differentiation of the several species, fossil and living, one from another, is often difficult to accomplish and must, in many instances, be regarded as merely a matter of individual and personal opinion. As an index fossil, in connection with critical stratigraphic work, it is evident that any fossil leaf of this general type would be of as little value as the leaves of Almis discussed in the preceding pages. In our existing flora the only species native to North America is F. grandifolia, and this species does not now extend further north than southern Ontario or further west than Wisconsin.