96 ROYAL SOCIETY OF CANADA 
Wood tracheids with large, bordered pits, numerous and compact in 
1 or often 2 rows, the orifice round. - 
Tangential—Medullary rays very resinous, 1-seriate or 2-seriate in part; the 
large cells thin-walled, uniform, rather equal, broad, round or oval or 
somewhat transversely oval to oblong. 
Silicification extreme, and the structure much altered by decay. 
One of the specimens of which a trial transverse section was made 
proved to be a species of Quercus, but the structure was so disorganized 
by decay and infiltration as to make further sections unprofitable, but 
in future collections from the same locality, species of oaks should be 
looked for. 
In 1896 Felix (4) described a wood from the Yellowstone National 
Park under the name of Rhamnacinium radiatum. Three years later, 
Knowlton (10, 769), with some hesitation, referred other specimens 
from the same locality to this species. In the course of a subsequent 
study of the flora of the Great Valley and Porcupine Creek in Saskat- 
chewan, Penhallow (13, 49) disclosed the fact that although this parti- 
cular species did not extend so far east, the genus was nevertheless 
represented in the Lignite Tertiary by at least two species, probably 
wholly distinct from those of Felix and Knowlton, which were described 
under the names R. porcupinianum and R. triseriatim. Now it is 
found that this genus once more appears in the material from Texas, 
but the specimen from this last locality cannot be correlated with any 
of those previously described. I have, therefore, thought best to describe 
it under a distinctive name which would indicate the general locality 
from which it was derived. 
RHAMNACINIUM TEXANUM, n. Sp. 
Figs. 1-3. 
Transverse—Growth rings medium, not very prominent, but defined by an 
abrupt alteration in the size of the vessels and by a zone of 2-4 
cells which are distinctly smaller and compressed radially. Wood 
cells round or hexagonal, thick-walled, very unequal and often in 
very unequal radial rows. Wocd parenchyma wanting. Vessels at 
first medium to large, single or upwards of 4, radially seriate, radi- 
ally oval and generally with conspicuous, thin-walled thyloses; thus 
continuing until the region of the summer wood without obvious 
alteration; chiefly 1, sometimes 2, or rarely 3 rows of vessels between 
two of the principal rays. Medullary rays prominent, 1, or more 
generally about four cells wide, the cells short, thin-walled and with 
squarish termination. 
Radial.—Ray cells all thin-walled and very variable, from four times longer 
than high, to short and twice higher than long, the two kinds min- 
