BERRY: MESOZOIC FLORA OF ATLANTIC COASTAL PLAIN 415 
analogous to those in the modern leaf, which may indicate the 
mode of origin of this peculiar character. This leaf seems to 
form a central figure from which a series of forms grade in several 
directions, culminating in quite dissimilar leaves. Lesquereux’s 
S. cretaceum is a more Platanoid leaf, with more acute tips, a 
tendency to become dentate, and with the primaries inserted 
nearer the base. Closely allied to the preceding is his S. (Araliop- 
sis) mirabile, which serves as a connecting link with his Platanus 
recurvata. From the aforementioned S. cretacewm of Lesquereux 
it is but a step to such a leaf as the one shown on Pl. 8. fig. 2, 
Later Ext. Fl., and to the trilobed forms referred to Cissites Har- 
kerianus, and these in turn grade into the more Cissoid forms of 
this species, such as those shown on Pl. 11. fig. 3, Cret. Fl. The 
primaries are basal and of not much greater caliber than the 
regularly succeeding straight secondaries. It is but a step from 
this leaf to that of Cissites Heerii on the one hand, with its pal- 
mately five-pointed blade; and to such forms as Cissites acumina- 
tus, pl. 5, fig. 4, Cret. and Tert. Fl., on the other; which in turn, 
by the elimination of the decreasing dentate points, gives us the 
leaf figured as 3, pl. 5, Cret. and Tert. Fl. In the second ‘series 
of leaves diverging from the typical, S. cretaceum, pl. 8, fig. I, 
Later Ext. Fl., is removed a slight distance by the shortening of 
the blade, the thickening of the primaries and secondaries, and 
the shortening and rounding of the lobes (S. obtusum); while a 
smaller leaf would be its logical descendant; and from these leaves 
to those referred to the typical Cissites salisburiaefolius is but a 
step. In the third series of leaves diverging from the typical 
S. cretaceum, we note that the leaf has its lobes much produced, 
narrow and running to a sharp point, as in the beautiful leaf on 
pl. 7. fig. 1, Later Ext. Fl., which however is still referred to S. 
cretaceum. Lesquereux’s S. acutilobum does not differ greatly 
from the preceding except in the direction of the lobes, which is a 
questionable specific character. From this leaf there is no great 
jump to those trilobed forms which are referred to Aralia Welling- 
toniana, the chief difference being in the margin. Thus we have 
an interrelated series connecting those leaves which seem to show 
affinity to Sassafras with those which suggest Platanus, and with 
others that suggest Cissites and Aralia. 
