HOLDEN. — CRETACEOUS PITYOXYLA. 619 



not be identified with Pinites Ruffordi which has tyloses in the trache- 

 ides and teeth in the ray parenchyma. One character absolutely puts 

 P. Ihiffordi out of the question, — it contains traumatic resin ducts, — 

 which as pointed out above, were not present here. It cannot be 

 placed with Pinus Natliorsti (15), which had thick-walled, unpitted 

 parenchyma around the resin canals and lacked tangential pitting, 

 or with Protopiceozylon antiquius Go than (19). That species had 

 thick-walled ray parenchyma, thick-walled epithelium around the 

 resin canals, three to four pits to each crossfield on the lateral walls of 

 the rays, and lacked tangential pitting, — features diametrically op- 

 posed to those of our fossil. Accordingly, our specimen cannot be 

 identified with any previously described. In view of the fact that the 

 leaves were borne on the main axis exclusively, rather than on short 

 shoots, it may appropriately be called Piiyoxylon foliosum. The only 

 other forms with such leaves are Pinus protoscleropitys and Prepinus. 

 With the former it cannot be identified because that form had such 

 abundant short shoots that it would be impossible to miss them, and 

 further it had ray tracheides. As suggested above, it may very proba- 

 bly be the wood of Prepinus. 



Pityoxylon anomalum n. sp. 



The third type of Pityoxylon differs from either of those previously 

 described, though similar to P. foliosum. Figure/, Plate 3, shows the 

 general topography of the stem. The annual rings are narrow and 

 indistinct. Resin ducts are present, extending in two planes, but as 

 is evident from a comparison of Figures b and e, Plate 3, — equally 

 enlarged — they are much less frequent in this specimen than in the 

 former. A further difference is that there is but one row in the first 

 annual ring; this row occurs in the primary wood. Figure a, Plate 4, 

 shows the character of the ducts. They are surrounded by a large 

 mass of epithelium, which is completely filled with resin. This 

 feature is best brought out in the longitudinal sections (Figures b, f, 

 and g) . The cells of this jacket are fairly thin-w^alled, and very heavily 

 pitted, which doubtless accounts for the abundant tyloses, which are 

 very thick-walled. As a rule there is but a single canal in each cluster 

 of parenchyma, — rarely there are two. 



The tracheides are badly collapsed, and the lumen usually com- 

 pletely obliterated. At times, however, in the better preserved 

 regions, the characteristics of the pitting may be made out. In the 

 lower part of Figure g, for example, a single row of pores may be ob- 



