228 CONIFERALES [ CHy 



features, as the association of primary and fascicular leaves, the 

 latter borne on brachy blasts subtended by a foliar trace.' 



Miss Holden^ has also described from New Jersey two species 

 which she compares with Prepinus, namely Pityoxylon foliosum 

 and P. anomalum. 



Pityoxylon Nathorsti (Conwentz). 



Under the name Pinus Nathorsti Conwentz^ described in 

 considerable detail specimens of petrified wood from the Senonian 

 Holma sandstone of Sweden, also a cone and two detached needles. 

 The rings of growth agree with those of stems and older branches 

 in the gradual increase in the thickness of the tracheid-walls in 

 passing from the spring to the late summer elements. The bor- 

 dered pits on the radial walls of the tracheids are uniseriate and 

 separate and none were found on the tangential walls. Both 

 horizontal and vertical lesin-canals occur, several of them with 

 well-preserved tyloses ; the epithelial cells are thin- walled and 

 unpitted as in Pinus silvestris. It may be that the abundance of 

 tyloses is connected with the presence of fungal mycelia as in 

 wood of Hevea stems recently described by Mr Brooks^. The 

 medullary are uniseriate, generally 5 — 7 cells deep, also fusiform 

 and with resin-canals : the preservation is not sufficiently good to 

 admit of any definite statement as to the occurrence of horizontal 

 tracheids. 



Pityoxylon zezoense (Suzuki). 



This Upper Cretaceous Japanese species was described as 

 Abiocaulis zezoensis*-, but in view of the occurrence of features 

 suggesting comparison with Pinus as well as with Abies the more 

 comprehensive generic name is preferable. In the presence of 

 pits on the tangential and horizontal walls of the medullary-ray 

 cells and in the pitting of the tracheids this wood conforms to the 

 Abietineous type. There are no ray-tracheids : the pitting on 

 the radial walls of the ray cells agrees in part with that in Abies 

 and in some of the cells there are large circular pits like those of 

 Pinus. Normal resin-canals are present in the second ring only, 

 others being inteipreted as traumatic. Xylem-parenchyma is 



1 Holden (IS'). 2 Conwentz (92) p. 13, Pis. i.— m., vi., vii. 



2 Brooks and Sharpies (14). ^ Suzuki (10). 



