[PENHALLOwW] CRETACEOUS AND TERTIARY PLANTS OF CANADA 45 
to this region again, detached areas of wood were found, while exter- 
nally to all there was a narrower zone of decayed woody tissue so 
modified as to resemble compressed and modified bark. The details 
of the microscopic examination are as follows: — 
Transverse. (Fig. 14). Growth rings strongly defined. Tracheids 
of the spring wood in very regular rows, squarish, about 52 x: 52 y, 
the walls 14 A thick, but the secondary layers more or less disin- 
tegrated and carbonized. Summer wood about 4-6 tracheids thick, 
the transition from the spring wood abrupt. ‘Tracheids about 
24 u wide, the walls about 12 x thick but much altered. Medul- 
lary rays prominent, one cell wide. Resin canals generally absent, 
but sometimes appearing in an imperfectly organized form on the 
outer face of the summer wood. Special resin cells are not to be 
distinguished from those in process of disintegration. 
Radial. (Fig. 15). Bordered pits on the radial walls of the 
tracheids in one row, about 28 « broad, distinctly bordered, the 
orifice round. Cells of the medullary rays constricted at the ends, 
about equal to 4? tracheids. The upper and lower walls thin and 
devoid of pits; the end walls thin, not pitted, straight or curved. The 
cells about 27 y high. Pits on the lateral walls not recognizable. 
Tangential. (Fig. 16). Medullary rays uniseriate, about 31:5 yu 
broad. 
This species has been found on two former occasions in the 
Cretaceous of Vancouver Island, and specimens of leafy branches 
from Port McNeil, described by Sir William Dawson in 1893, are 
reported by him to be indistinguishable from specimens derived from 
the Laramie and Middle Tertiary. “It would seem to range from 
the Upper Cretaceous to the Miocene inclusive.” The fact that no 
other species of Sequoia has been reported from the Cretaceous of the 
same locality, would seem to justify reference of our present material 
to it. 
Comparison with existing species shows that S. langsdorfii bears 
a very striking resemblance to S. sempervirens with respect to the 
structure of the wood. How far this may prove identity it is impos- 
sible to say at present, since the wood of S. langsdorfii is deficient 
in some essential structural features, but it may be noted that the 
resemblance is most marked with respect to the general structure, the 
character of the growth rings, and more particularly as established 
through the medullary rays and the occurrence of imperfectly formed 
resin passages. 
Sec. IV., 1902. 3. 
