7 
divided unequally by one or several smaller, shorter, and generally 
simple nerve-branches which run parallel with the large ones, 
sometimes connecting with the exterior net-work; all the spaces 
between tlie lateral nerves occupied by a relatively coarse reticu- 
lation. 
Although so different from the leaves described under the 
names of L. oblongifolium and L. quercifolium, these have in 
common with them the peculiar angular emargination so charac- 
teristic of the genus, and essentially the same nervation. The 
more elongate and lanceolate form represented on Plate LXIL., 
figures 3, 4, occurs in considerable numbers, and may perhaps 
represent a distinct species, but others are broader and more 
ovate, like those represented in Plate LXII., figure 2. 
slaken by themselves, these two forms would be. regarded as 
specifically different, but there are connecting links between 
them, and we must regard the several shapes as showing simply 
the variation of foliage so common in other trees. Prof. Heer 
in his Flora Arctica, Vol. VI., Plate XXII., has represented a 
number of leaves which apparently belong to the same species with 
those now under consideration. All these he regards as varieties 
of L. Meekit, first described by him from the Dakota sandstones, 
but it seems to me that they do not represent either of the two 
forms from the Dakota group, neither of which have yet been 
found in Greenland. “ence, until more material shall show the 
simple, ovate or lanceolate forms to be connected by insensible 
gradations with others, I must regard them as specifically distinct. 
EXPLANATION OF FIGURES. 
Plate LXI., Fig. 1.—Lzriodendron oblongifolium, N., 
Amboy Clays, New Jersey. 
Fig. 2.-~Liriodendron primevum, N., 
Dakota Group, Nebraska. 
: Figs. 3. 4—Lzriodendron Meekit, Heer, 
Dakota Group, Nebraska. 
Plate LXIL., Fig. 1.—Liriodendron quercifolium, N., 
Amboy Clays, New Jersey. 
Figs. 2, 3, 4.—ZLiriodendron simplex, N., BY 
(L. Meehii, Heer in part, Atane, Greenland) Amboy Clays, New _ 
Jersey and Long Island- ee 
