416 OLDER MESOZOIC FLORAS OF UNITED STATES. 
CycaDELLA Kyicgutir Ward. 
Pls. CLXXJI-CLXXVII. 
1900. Cycadelia Knightii Ward: Proc. Wash. Acad. Sci., Vol. I, p. 283, pl. xxi. 
Trunks very large (80 to 40 em. high, 19 by 28 cm. in diameter), 
subellipsoidal, somewhat laterally compressed, unbranched, depressed 
at the summit; axis eccentric; rock hard, somewhat mineralized, 
dark colored or nearly black, of high specific gravity ; organs of the 
armor horizontal; rows of scars from left to right forming an angle 
of 45° with the axis, those from right to left of 70°; leaf scars sub- 
rhombic or subelliptical, 18 to 20 mm. wide, 8 to 12 mm. high; leaf 
bases hard, punctate; walls 3 to 5 mm. thick, hard, striate, with or 
without a median groove; reproductive organs few, poorly developed, 
flush with the surface or slightly raised, elliptical in cross section, 
2 by 3 cm. in diameter, surrounded by large subrhombic involucral 
bract scars passing into leaf scars, the central portion solid and show- 
ing the scars of the floral organs; armor 4 to 6 cm. thick, obscurely 
attached to the axis; woody zone 3 to 4 cm. thick, undifferentiated; 
medulla 6 by 10 cm. in diameter, difficult to distinguish from the 
woody zone, hard and black, with flinty or crystalline areas. 
The next largest specimen in the collection, and probably the finest, 
from the standpoint of symmetry and general appearance, is No. 500.65. 
It came in two pieces of unequal size, caused by a transverse fracture 
below the middle. The larger piece weighs 15.48 and the smaller 9.8 
kilograms, making the total weight 25.28 kilograms. There was one 
other specimen, viz, No. 500.33, which so closely resembles this that 
it is impossible to separate it. It consists of considerably over half 
of the lower portion of a somewhat smaller trunk, having the base 
perfect and a nearly horizontal transverse fracture across the trunk 
above This weighs 8.87 kilograms. 
Ltake great pleasure in dedicating this fine species of Cycadella to 
Prof. Wilbur C. Knight, State geologist of Wyoming, through whose 
enterprise the collection was made, and who has so generously placed 
it in my hands for elaboration. 
Pl. CLXXII represents the best-preserved side of No. 500.65, PI. 
CLXXIII its base, and Pl. CLXXIV the upper transverse fracture 
of the lower piece. Pl. CLXXYV is the best side view of No. 500.35, 
Pl. CLXXVI its base, while in Pl. CLX XVII we have a representa- 
tion of the upper transverse fracture. 
The following is a list of the twenty species of Cycadella in the order 
in which they have been described: 
1. Cycadella Reedii. 4. Cycadella Knowltoniana. 
2. Cycadella Beecheriana. 5. Cycadelld compressa. 
3. Cycadella wyomingensis. 6. Cycadella jurassica. 
