66 THE FLORA OF THE AMBOY CLAYS, 
yation is more flowing and simple, less contorted and tangled, than in any 
species of the genus Populus known to me. They closely resemble, how- 
ever, those leaves found in the Upper Cretaceous of Greenland which have 
been called by Professor Heer P. hyperborea and P. Berggren (Fl. Foss. 
Aret., Vol. VI, Abth. II, pp. 63, 64), and since no generic relationship that 
is more plausible suggests itself, perhaps it is well enough to leave them 
there for the time being. 
Locality: Woodbridge. 
SALIX PROTEMFOLIA Lesq. 
JEG SVAN, Kas oh ee 
Salix protewfolia Lesg., Am. Jour, Sci., 2d series, Vol. XLVI, p. 94; Cret. Fl., p. 60, 
Pl. V, tigs. 1-4. 
In the figures cited above are represented two slabs of clay upon the 
surtace of which are spread out twigs and leaves of a willow which I have 
been unable to distinguish from Salix proteefolia Lesq. (Cret. FL, p. 60, 
Pl. V, figs. 1-4), and yet, as the nervation is too imperfectly represented 
in both the impressions in the Dakota group and those from the Amboy 
Clays, it is impossible to insist upon the identification. It is manifest, 
however, that this species differs from Salix membranacea from the same 
beds in having the base wedge-shaped instead of rounded. Further com- 
parisons will be necessary before the relations of these leaves to the genus 
Salix and to the species with which they have been compared can be satis- 
factorily determined. 
Locality: Woodbridge. 
SALIX MEMBRANACEA Newb. 
Pl. XXIX, fig. 12. 
Salix membranacea Newb., Later Extinct Floras, p. 19; Illustrations of Cretaceous and 
Tertiary Plants, Pl. I, figs. 8, Sa.' 
Leaves petioled, smooth and thin, lanceolate, long-pointed, rounded or 
abruptly narrowed at the base, near which they are produced, margins 
i Thereference is to the plates of an unpublished work. Twenty-six of these plates were, indeed, 
published in 1878, under the title Illustrations of Cretaceous and Tertiary Plants, the figures having 
been independently identified by Professor Lesquereux. Dr. Newberry, however, did not accept all 
these identifications. For example, on the above-quoted Pl. I, figs. 5-8 were referred to this species, 
while Dr. Newberry refers figs. 5-7 to S. cuneata (see bibliography, p. 18).—A. H. 
