1906 | JEFFREY & CHRYSLER—CRETACEOUS PITYOXYLA 3 
oxylon is considered by some paleobotanists not to antedate the 
Tertiary.4 
The specimens of Pityoxylon, which have served as the material 
for the present investigation, consist for the most paft of cylindrical 
fragments, which are sometimes as thick as 10°™ and often twice 
as long. Most of them however are of smaller size. Where the 
pieces are cylindrical they generally include the pith in a good state 
of preservation, a feature of some importance in connection with 
their diagnosis. It is not possible to state absolutely from the nature 
of the specimens whether they represent smaller branches or merely 
the core of larger axes from which the external layers have been 
burned off. From the ordinarily tylosed condition of the resin 
canals, it may be inferred with a strong degree of probability that 
the latter supposition is more likely to be correct. Angular frag- 
ments showing annual rings with a large radius of curvature permit 
a study of the structure of the older wood. Although at least two 
different species of fascicles of pine needles and at least as many 
species of cone scales of Pinus, all in an admirable condition of 
preservation, have been found in association with the Pityoxyla 
from the Androvette pit, it has not been possible to distinguish in 
these lignites more than one type of wood structure. The material 
in this respect presents an interesting parallel to the condition found 
by CONWENTZS to exist in the Pityoxyla of the Eocene or early Oligo- 
cene, which bear the well-known Baltic amber; for this author 
declares that he is unable in the vast variety of fossil succiniferous 
woods which have passed under his inspection to diagnose more 
than a single species. The absence of clearly marked criteria for 
the separation of species on the basis of wood structure is not sur- 
prising, since even in the case of living pines it is difficult to do more 
than segregate the various species into larger groups or sections 
on the characters offered by the wood. 
Fig. 1 shows the structural features of a transverse section of 
a slightly flattened branch about 5°™ in thickness in its greatest 
diameter, and showing more or less distinctly about twenty annual 
4Cj. GoTHAN, Zur Anatomie lebender u. fossiler Gymnospermen-Hélzer 88, 
Herausgeb. von der Kéniglich Preussischen pcologischen Landesanstalt. und 
B ie. pp. 108. Berlin, r905. 
5 Monographie der Baltischen Bernsteinbiume. Danzig, 1890. 
