194 CONIFERALES 1-CH. 



resin-canals. Dr Stopes draws attention to certain features, 



particularly the pitting of the medullary-ray cells and the structure 



of the cortex, in which this species resembles the genus Crypto- 



meria. 



Cwpressinoxylon Hortii Stopes. 



This Lower Greensand species ^ from Bedfordshire is distin- ' 

 guished from other types by the very numerous medullary rays, 

 often separated from one another by a single row of tracheids, 

 which are both uniseriate and multiseriate, the same ray exhibiting 

 both forms at different heights. The rays attain a depth of 80 

 cells and there is generally one large oval or circular pit in the field 

 (fig. 717) though two are occasionally present. This species is 

 hardly a typical Cupressinoxylon and Dr Stopes points out that 

 the large single pit in the field is suggestive of Podocarpoxylon : it 

 affords another illustration of the impossibility of identifying the 

 majority of fossil woods within narrow limits. 



C ujjressinoxylon Holdenae sp. nov. 



A species of Eocene age from the London Clay of Faversham 

 in the Cambridge Botany School collection characterised by well- 

 defined annual rings and the presence in some but not all the bands 

 of summer-wood of resin-canals (fig. 718, C) which vary in size, 

 some of the larger being formed by the confluence of smaller 

 adjacent canals. The presence of rather thick- walled, pitted, cells 

 lining the canals or in close association with them is a characteristic 

 feature. Tyloses occur in some of the canals. The large number 

 of canals in each row suggests their development in response to 

 traumatic stimuli. The bordered pits occur in single, separate, 

 rows or in double and opposite rows with rims of Sanio occasionally 

 preserved. In a few places the pits of a single row are in contact 

 and slightly flattened. Resin-parenchyma occurs in vertical rows in 

 both spring- and summer-wood. Medullary rays uniseriate, reach- 

 ing occasionally 30 cells in depth; the tangential and horizontal 

 walls are unpitted and on the radial walls the pits are preserved 

 only in a few places ; there appear to be 2 — 4 fairly large simple 

 pits in the field. The crowded series of canals (fig. 718, C) are 

 identical with the traumatic ducts described in Sequoia sempervirens^ 



♦ Stopes (15) p. 194, PI. xvni. text-figs. 56 — 58. ^ Jeffrey (03). 



