WARD] JURASSIC CYCADS FROM WYOMING. 411 
dark or black on freshly exposed ones, of medium specific gravity; 
organs of the armor horizontal; leaf scars subrhombic, 15 to 20 mm. 
wide, 7 to 10 mm. high; leaf bases hard, rough or porous, with a 
raised ridge near the margin indicating the position of the vascular 
bundles, which are themselves sometimes visible in the form of pits; 
walls 2 to 5 mm. thick, hard and somewhat porous, light colored with 
darker strie; reproductive organs numerous, well developed, promi- 
nently projecting in the form of large warty protuberances distorting 
the arrangement of the leaves, elliptical in cross section, 20 by 30 mm. 
in diameter, surrounded by large, narrowly subrhombic bract scars in 
several rows passing into leaf scars, central portions heterogeneous, 
marked by the scars of the essential organs; armor 2 to 5 cm. thick, 
clearly but irregularly joined to the axis; woody zone 15 mm. thick, 
not differentiated; medulla'a thin slab 3 to 6 cm. thick, 15 cm. wide, 
of a fine uniform structure resembling the white iron ore of the Poto- 
mac beds of Maryland. 
Nos. 500.27, 500.32, and 500.64 are referred to this species. The 
last is anomalous and shows relatively few of the characters, but it 
has the same shape. The fruits are little elevated, but otherwise this 
leading character holds for it. No. 500.27 is probably the top of the 
same trunk as No. 500.32, but there is an interval between them, and 
they have been subjected to different conditions since they became fos- 
silized. Ona casual view, therefore, they do not seem so closely to 
resemble each other as they do when carefully inspected. They are 
then found to have almost exactly the same width, thickness, and gen- 
eral form, so that it is easy to see which sides correspond. All the 
characters also agree except that the fruiting axes are more promi- 
nent on No. 500.82, representing the lower portion. This is partly 
due to the fact that this specimen has suffered more from erosion, 
and owing to the greater hardness of these organs they are made to 
stand out more conspicuously. It was the appearance thus produced 
that suggested the specific name. 
No. 500.27 weighs 5:19, No. 500.82, 8.81, and No. 500.64, 4.68 kilo- 
grams. 
In Pls. CLV and CLVI the two specimens, Nos. 500.82 and 500.27, 
are represented from opposite broad sides in the position in which 
they are supposed to have existed as a trunk, but for want of space 
on the plate they had to be brought practically together, whereas, as 
already stated, the theory of their identity requires the assumption of 
a certain amount of loss between these parts. Pl. CLV, Fig. 1, shows 
the warty projections better than any other. PI. CLVIL is the only 
view taken of No. 500.64 and represents its best side. 
