Bulletin 3. The flora of the Raritan Formation, 1911 - State of New ...

I42 THE RARITAN FLORA.
nearly 9°° , and the lobes in the modern leaf have their margins
inflated and not straight. In these ancient leaves the
sinus seldom has a marginal vein, the secondary in this region
usually forking and striding it, or curving to join its neighbor.
The secondary system seems to be uniform thron_ont the
leaf, while in the modem leaf there is always evidence of changed
conditions in that region arotmd the sinus; the secondaries or
their representatives from both the primaries and midrib are
changed fi_size and direction, and usually belong to the tertiary
system. None of the Dakota leaves of this species show the
characteristic basal venation of the modern leaf, While we
shonld not, necessarily, expect Cretaceous species to conform to
the modern type, still the character of the secondary system in
tile former is so different from what would obtain in a leaf
descended from a simple ancestor, such as Sassafras is thought
to have done, that .we are inclined to associate these leaves with
those trilobed forms which have been referred to, Aralia or
Sterculia_ laying aside, for the present, any consideration as to
whether or no they are true species of Aratia and Sterc_lia.
However, in view of the present uncertainty, grid because of
the havoc to the stratigraphie value of these leaves which would
be wrought by any change of name, they are retained in the
genus Saa'safras pending more positive evidence of their affinity.
Occurrence.TWoodbridge, Milltown.
Collections.--N. Y. Botanical Garden.
_A_SAFRAS
PROGENITORHollick.
Plate XVIII, Fig. I,
Sassa[ras progem;tor Hollick, Bull. Torrey Club, vol. :zI:53,
pl. I74, f. x, I894; B'ull. Geol. Soc. Amer., vol. 7: 13,
1895; U. S. Geol. Stow. Mon. 5o: 78, pI. 3o, [. Iz,
19o7.
Newb., F1. Amboy Clays, 88, pl. 27, f. *-3, 1896.
Berry, Bot. Gazette, vol. 34: 443, 19°2; Bull. Torrey Club,
rot. 31 : 78, pl. I, f, 3, I9o4-
NEW JERSEY GEOLOGICAL SURVEY