WARD.) THE BOULDER CYCAD. 379 
trunk, those passing from left to right forming an angle of about 30° 
and those from right to left of about 45° with the vertical axis; scars 
of the usual size, nearly triangular in shape, rarely somewhat arched 
above, but sometimes concave, so as to appear inversely heart-shaped, 
the upper side of the triangle nearly horizontal, the other two sides 
in line with the rows of scars, thus making different angles with the 
axis, the three angles all sharp, averaging 20 mm. wide by 15 mm. 
high, while the right and left sides of the triangle are respectively 
16 mm. and 18 mm.; leaf bases always present 1 to 3 cm. below the 
surface, their summits level or slightly concave indicating a natural 
plane of disarticulation, presenting a roughened or spongy surface 
without pits or visible bundle scars, usually traversed by thin longi- 
tudinal dikes crossing one another at varying angles; ramentaceous 
walls very thick, 5 to 8 mm., with thickenings in the angles of the 
scars often as large as the scars themselves, rough and wrinkled on the 
outer edges, homogeneous but having a very thin (0.5 mm.) layer . 
lining the inside of the scars, which may be the periderm of the peti- 
oles; reproductive organs very abundant and well developed, one in 
the axil of each leaf standing over the upper side of the scar and 
sometimes depressing it so as to cause the inversely heart-shaped 
appearance of the scars, making the walls on that side very thin or 
removing them altogether and exposing the bud on the upper side 
of the scar, elliptical in cross-section, 25 mm. in horizontal and 15 mm. 
in vertical thickness, their summits flush with the upper edges of the 
walls or rising slightly above them, rarely projecting, always filled 
with the remains of the organs composing them and showing a con- 
centric structure with a heterogeneous center, the crescent-shaped 
involucral bract scars mostly at the ends of the ellipses and extending 
far out along the walls, sometimes aggregated at other points denot- 
ing abortive buds; armor very thick, 5 to 6 cm., separated from 
the axis by a definite but irregular or jagged line; woody zone 2 to 
7 em. thick, consisting of a homogeneous, black, cherty or partially 
chalcedonized substance showing concoidal fracture without division 
into rings or traces of bundles or medullary rays; medulla faintly 
distinguishable from the wood, compressed into a slab 3 cm. thick and 
90 to 25 cm. wide in the only specimen known. 
A large specimen of a trunk that was much compressed laterally, 
containing more than half the basal portion. It is broken by a some- 
what even vertical fracture in the plane of the minor diameter a little 
to one side of the center, and also broken across obliquely above, so 
that the vertical fracture constitutes the shorter side. The amount 
that is wanting above is unknown, but Dr. Knowlton’s statement that 
‘* it is said to have been two or three times as long,” was probably an 
exaggeration on the part of his informant. Still, it might well have 
been considerably longer. It is scarcely at all worn, and is in an 
