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PINITES RUFFORDI, FROM THE ENGLISH WEALDEN FORMATION. 425 
of a new specific type of the genus Pinites. A comparison of 
Pinites Ruffordi with the type described by Géppert and Menge,* 
and more fully by Conwentz,t reveals a striking similarity 
between the Wealden aud Eocene plant. The species more 
recently described by Conwentz as Pinites Nathorsti,t from the 
Lower Cretaceous Holma Sandstone of Sweden, agrees very 
closely with P. Ruffordi; in the former there are the same 
parenchymatous filled canals, and other points of resemblance ; 
but in the Swedish species the bordered pits appear to occur 
only in single rows on the radial walls of the tracheids, 
Unfortunately it is seldom possible to connect petrified 
coniferous stems with their leaf-bearing branches and cones, 
and in this species we are ignorant as to the leaves and flowers 
borne by the branches of Pinites Ruffordi. In any case we 
have abundant evidence of the existence in Wealden rocks 
of a conifer possessing anatomical features practically identical 
with those characteristic of recent species of the genus Pinus. 
EXPLANATION OF PLATES. 
The figures are approximately 240 times natural size. 
PuateE II. 
Figs. 1 and 2. Transverse section showing well marked zones of summer 
(autumn) wood, medullary ray cells, and (in fig. 1) a resin duct. 
Fig. 3. Resin duct filled with crystalline material. 
4. Resin duct, with small cavity, surrounded by some tiillen-like cells 
and partially disorganised xylem parenchyma. 
Puate III. 
Fig. 5. Resin duct filled with large rounded cells. 
6. Tangential section showing tracheids and a broad medullary ray 
traversed by a resin duct. 
7. Tangential section showing the different lengths of medullary rays. 
Figs. 8 and 9. Radial section of pitted medullary ray cells. 
10 and 11. Bordered pits on the radial walls of tracheids. 
* Géppert and Menge, ‘ Die Flora des Bernsteins,’ vol. i. 1883, p. 27. 
t+ Conwentz, loc. cit. 
t Conwentz, ‘Untersuchungen tiber fossile Hiélzer Schwedens,” in 
“Svensk. Vet.-Akad. Handl.,’ vol. xxiv. No. 13 (1892), p. 13, pls. 1, 2,3, 
6, and 7. 
