3802 OLDER MESOZOIC FLORAS OF UNITED STATES. 
Class BENNETTITALES. 
FAMILY BENNETTITACEA. 
Genus CYCADEOIDEA Buckland. 
CycapEorpEA Emmonst (Fontaine) Ward. 
PL. XLIIL, Fig. 3. 
1857. Impression or cast of a part of a trunk of acycad Emmons: American Geology, 
Pt. VI, p. 128, fig. 92a on p. 124. 
1883. Zamiostrobus Emmonsi Font.: Older Mesozoic Flora of. Virginia, Mon. U. 8. 
Geol. Survey, Vol. VI, p. 117, pl. lii, fig. 5. 
1894. Cycadeoidea Emmonsi (Font.) Ward: Proc. Biol. Soc. Washington, Val. IX, 
p. 86.1 
Emmons, in Pt. VI, pp. 128, 124, fig. 99a, gives a description of an 
imprint of a trunk of a small cycad which he does not name and for 
which he gives no locality. The original of this is probably the form 
given in Fig. 3 of Pl. XLIII. If so, Emmons’s figure does not give 
a good representation of it, either for the shape of the trunk or for 
the character of the leaf scars. Nearly the whole of the trunk is 
10n the occasion of my visit to Williams College, mentioned above (p. 276), I found the original 
of Emmons’s fig. 92a, and after a somewhat careful examination of it, I took the following notes: 
“This is nothing but a thin slab of light-colored shale bearing on its reverse side an impression of 
avery broad cycadean leaf. The slab is only 15 mm. thick. It is fissile and other plant impres- 
sions occur at other planes of cleavage within it, as seen by their projecting ends. On the side of the 
cycad a label is glued, on which are written, probably in Dr. Emmons’s‘hand, these words: ‘Impres- 
sion of a trunk of a cycad.’ 
The right half of the impression is dark or nearly black, due to a thin deposit of carbon. This is 
partly worn off by handling, but remains at the bottom of the depressions. On the left it gradually 
fades out and probably never existed near the left margin. It is probable that the rounded conical 
form at the top and on the right side correctly represents that of the trunk, but on the left below the 
slab is so broken as to carry away a part of the impression. The general concavity is slight, and if it 
indicated the curvature of the surface the trunk would have been rather large, but from the small 
size of the scars and their spiral arrangement it seems to have been small, or not more than twice 
the diameter of the impression. m 
With the exception of the abrupt break on the left the cleavage all round isin the nature of a 
diagonal cross fracture from one natural plane to the next below it, and although not shining seems 
to be aslickenside. This condition gives the impression a sort of relief. It is evident that the top of 
the impression does not reach the top of the trunk, and the whole represents a small area of the side 
of a trunk near the top. It is difficult to determine the exact position of the axis, but the impression 
is probably nearly vertical. The impression is 7 cm, high and 6 cm. wide, maximum measurements, 
The leaf scars are arranged in two spiral rows, those arising from left to right being nearly hori- 
zontal, but curving so as to have an angle near the summit of about 45°. The other set of rows are 
vertical at the lower end, but curve slightly to the left, reaching the summit at an angle of 10° or 15°, 
The scars are very small and almost exactly rhombic,with a large differerice between the long and 
short sides. The long diagonal, which is usually nearly vertical, is about 7 mm. and the short, nearly 
horizontal one4mm. The long side is nearly 5 mm. and the short side scarcely more than 3 mm. 
The ramentum walls are over 1 mm. thick, with a distinct central raised ridge, which probably 
represents a commissure. As the scars are depressions surrounded by these walls, it is evident that 
the bases of the petioles were present and rose above the ramentum walls, also that their outer ends 
were convex, so as to produce these concave depressions. 
There is nothing on the impression from which the existence of fruiting axesor buds can be 
