LA 
[PENHALLOW ] NOTES ON FOSSIL WOODS FROM TEXAS 95 
wood abrupt. Tracheids of the spring wood large, upwards of 70 x 
84 u, the walls upwards of 21 ym thick; very uniform and equal in 
very regular rows; rounded hexagonal or those of the earlicst growth 
much elongated radially. Resin canals wholly wanting. Resin cells 
usually numerous throughout, prominent, scattering. Resinous tra- 
cheids sometimes present and forming more or less extensive tracts. 
Rudimentary resin sacs sometimes appear on the outer face of the 
summer wood. 
Radial.—Medullary rays without tracheids; the parenchyma cells equal to 
about 4 wood tracheids; straight or somewhat contracted at the 
ends; the upper and lower walls thin and entire; the terminal walls 
thin and not pitted, straight or curved; the lateral walls with rather 
large, round pits, 1 or chiefly 2 per tracheid. Bordered pits round, 
numerous and chiefly in two rows. 
Tangential—Medullary rays 1-seriate or rarely 2-seriate in part, low to 
medium; the large cells about 31.5 y broad, round or oval, chiefly 
uniform, but more or less unequal. 
Material highly silicified, but the structure fairly well preserved. 
Among the specimens from Porcupine Creek and Great Valley 
already referred to, there was a hitherto undescribed species of Cupress- 
oxylon, which I then described under the name of C. dawsoni (13, 46). 
This wood has not reappeared in any of the Eocene deposits examined 
by me until it was found among the material from Texas. From this 
latter place, the material was found to be very much in the same state 
of preservation as the wood from Saskatchewan, but as it presents in 
a recognizable form, some features of structure not determinable in 
the first specimens, the diagnosis is herewith recast, but reference mav 
be made to the original paper for details presented by photographs of 
the structure. | 
CUPRESSOXYLON DAWSONT, Penh. 
Eocene of the Great Valley and Porcupine Creek Groups, Saskatchewan; 
Yegua Clays (Eocene) of Somerville, Texas. 
Bib.:—Dawson, B. N. A. Bound, Comm., 1875, App. A, 331: Knowlton, Cat, 
Cret. and Tert. Floras, 80: Penhallow, Trans. R. S. (Canada), IX, 
iv, 46. 
Transverse—Growth rings broad. Tracheids of the spring wood large, about 
42.1 u x 40.4 mw; thin-walled, squarish-hexagonal, rather uniform 
and equal; the spring wood passing somewhat gradually into the 
thin summer wood which is composed of 2-4 rows of slightly 
smaller, radially flattened and thicker-walled tracheids. Medullary 
rays resinous. Resin canals wholly wanting. Resin cells numerous 
throughout the growth ring, scattering or somewhat zonate. 
Radial.—Medullary rays very resinous, devoid of tracheids; the cells straight; 
the upper and lower walls thin, apparently entire; the terminal walls 
entire, straight or curved; the lateral walls with oval or round pits, 
several per tracheid, the correct number not readily determinable. 
