414. Berry: Mesozoic FLORA OF ATLANT C COASTAL PLAIN 
Pl. pl. 6. f. 1-4. 1878. Mon. U.S. Geol. Surv. 35: 98. pl. 6. 
f. 1-4; pl. 8. f. 1, 2 (not pl. 7. f. 1-3). 1898. Lesquereux, 
Cree. Fl. So. A at. 1, 2; ple 72..f. 2. 1878... "Kurtz, 
Revista Mus. La Plata 10. 1902. Berry, Bot. Gaz. 34: 444. 
1902. 
Description: ‘‘Leaves petiolate, decurrent at base, very 
smooth above, strongly nerved below; three-lobed; lobes entire 
and acute. The nervation is all strongly defined; the central 
nerve straight or nearly so; the lateral primary nerves springing 
straight outward till they approach the margin of the lobes, when 
they are abruptly curved and run together. From these the 
tertiary nerves are given off at a right angle, and from these the 
quaternary nerves spring at a similar angle, together forming a 
network of which the areoles are subquadrate.’” Newberry, 1868. 
Professor Newberry includes under Sassafras cretaceum the 
various forms described by Professor Lesquereux as S. Mudget, S. 
subintegrifolium, S. integrifolium, S. obtusum, S. cretaceum denta- 
tum, S. cretaceum obtusum, S. acutilobum, Cissites Harkerianus, 
and C. salisburiaefolius. While this shows the undoubted com- 
posite nature of S. cretacewm, it shows also that the extremes of 
leaf form above mentioned are so closely connected with the more 
typical leaf by a series of intermediate forms that the question of 
where one species shall end and another begin is an extremely 
difficult one. | 
The writer considers the leaf figured on pl. 6. fig. 1, Later Ext. 
Fl., to be the typical form of this species, thus agreeing with 
Newberry’s original description and with his later opinion ex- 
pressed in 1898. This type bears considerable resemblance to 
some modern Sassafras leaves. A slight widening of the terminal 
lobe of some of these in the basal region would give a leaf strikingly 
like S. cretaceum; or, were the sinuses of the latter slightly deeper 
we would have the typical modern leaf. The basal portion of the 
leaf is like Sassafras, and the indications point to a similar vena- 
tion in this region. The first pair of secondaries do not branch 
to form margins of the sinuses; the left one runs directly to the 
sinus, however, and may possibly have conformed to the margin 
and been effaced in the specimen; the right one is stronger and 
runs almost to the sinus, where it makes a sharp turn upward, 
continuing until it joins the next secondary. This feature is 
