412 OLDER MESOZOIC FLORAS OF UNITED STATES. 
CYCADELLA JEJUNA Ward. 
Pls. CLVITI-CLXI. 
1900. Cycadella jejuna Ward: Proc. Wash. Acad. Sci., Vol. I, p. 279. 
Trunks of medium size (18 cm. high, 7 to 12 cm. in lesser, and 16 to 
20 cm. in greater diameter), ovoid or subconical, laterally compressed, 
unbranched; rock hard, gray on weathered surfaces, drab in the inte- 
rior, black on fresh exposures, with rather high specific gravity; organs 
of the armor horizontal; rows of scars forming an angle in either 
direction of 45° to 50°; leaf scars subrhombic, 15 to 20 mm. wide, 7 
to 9mm. high; leaf bases hard and firm, rough on the exposed ends; 
walls 2 to 4mm. thick, light colored and contrasting with the leaf bases, 
sometimes with a median ridge; reproductive organs few and poorly 
preserved; armor 2 to 4 cm. thick, joined to the axis by a clear line; 
wood 15 to 20 mm. thick; outer zone 5 mm. thick, traversed by rays 
or vessels; inner zone consisting of two rings, the outer 5 mm. thick 
with fine radiate structure showing medullary rays and woody wedges, 
the inner 5 to 10 mm. thick of a less definite structure; medulla 
elliptical in cross section, lesser diameter 2 to 8 cm., greater 8 cm., 
homogeneous. 
The two specimens, Nos. 500.28 and 500.31, which I have brought 
together here, have at first view very little to mark them or interest 
the student, but while they differ essentially from all others in the 
collection, they resemble each other in all the main points. No. 
500.28 is smaller and more compressed, and is mostly black on the 
outer surface, but the outer coating has pretty much entirely disap- 
peared and the leaf scars are clearly exposed. The fracture at the 
base also reveals some very definite internal structure. No. 500.31 
shows much less, but so far as visible the characters are the same. 
The former weighs 2.33 and the latter 3.97 kilograms. The specific 
namé refers to the somewhat negative and meager character of the 
specimens. 
Pls. CLVIII and CLIX show opposite sides of No. 500.28, and Pls. 
CLX and CLXI those of No. 500.31. In the former of these speci- 
mens scarcely any ramentum remains on the surface and the leaf scars 
are quite clearly shown. The same is true for one side of No. 500.31, 
but the other side, represented on Pl. CLXI, shows the area over 
which it has been scaled off along a definite fins, and the edgé of it is 
distinctly visible. 
CYCADELLA CONCINNA Ward. 
Pl. CLXIL. 
1900. Cycadella concinna Ward: Proc. Wash. Acad. Sci., Vol I, p. 280. 
Trunk small (12 cm. high, 14 by 15 cm. in diameter), irregu- 
larly and obliquely short-conical, somewhat vertically compressed, 
