WARD] JURASSIC CYCADS FROM WYOMING. 895 
The Yale specimen weighs 3.18 and the Knight specimen 1.45 kilo- 
grams. 
Pl. LX XVII represents the inner fractured surface of the specimen 
as restored, the lines separating all four of the pieces being distinctly 
visible. Pl. LX XVIII shows the outer surface of the same. 
CYCADELLA WYOMINGENSIS Ward. 
Pls. LX XIX-XC. 
1900. Cycadella wyomingensis Ward: Proc. Wash. Acad. Sci., Vol. I, p. 266, pl. xvii. 
Trunks relatively large (25 to 30 cm. high, 15 to 25 cm. in diameter), 
short-conical or slightly contracted at the base, more or less laterally 
compressed, unbranched or with a few projecting secondary axes; rock 
substance hard and fine-grained, generally light colored but with vary- 
ing shades, of medium specific gravity; organs of the armor slightly 
ascending; rows of scars from left to right making an angle with the 
axis of 70° to 80°, those from right to left of 45°; leaf scars sub- 
rhombic, 15 to 20mm. wide, 8 to 12mm. high; leaf bases relatively 
dark, affected with black or sometimes white tubular punctations; 
walls 2 to 4mm. thick, light colored and striate but without any proper 
commissure; reproductive organs few but often well developed, some- 
times projecting or passing through the outer coating, elliptical in 
cross-section, 2 by 3cm. in diameter, surrounded by mostly obscure, 
rather large involucral bract scars of variable shape, the central por- 
tion solid but heterogeneous in structure; armor 3 to 6 cm. thick, joined 
to the axis by a definite but usually irregular, sometimes scalloped, 
line; wood 3 to 4cm. thick; cortical parenchyma 10 to 15 mm. thick; 
fibrous zone 1 to 2cm. thick, usually consisting of two rings, one or 
both radiate in structure, the medullary rays often distinct; medulla 
5 to 10cm. in diameter, the cross-section elliptical in the compressed 
specimens, of a nearly homogeneous fine-grained structure. 
This species includes some of the handsomest specimens in the collec- 
tion, having about a medium size, and therefore being fairly representa- 
tive of the Jurassic cycads. Nos. 500.3, 500.14, and 500.15 are nearly 
perfect trunks. The rest are fragments. Nos. 500.7 and 500.20 are 
somewhat thin segments bounded by transverse fractures, and almost 
certainly belong to the same trunk at different elevations. No. 500.26 
may be a lower segment of the same trunk, but if so it must have been 
contracted at the base, as is the case with No. 500.3. Nos. 500.8 and 
500.67 fit each other, and the former, which was shattered when 
received, has come in three pieces. It represents a section between two 
oblique but chiefly vertical fractures. No. 500. 52, a thick, somewhat 
cubical piece, almost certainly belongs to No. 500.8, as shown by the 
identical structure of its principal fracture. 
