100 DESCHIPTIYE CATALOGUE 



smaller. In transverse section the preservation is such that the 

 bordered pits show up remarkably well both in the radial walls 

 throughout and in the tangential walls of the autumn wood. 



Resm-contaiiiiny vylem-parenchyma cells are very numerous 

 ns can be seen in transverse and longitudinal sections (Pis. XVI 

 & XVII, >./>.). They may be radially narrower or equal in 

 size to the adjacent tracheids. In longitudinal section the cross- 

 walls of the series of cells lie horizontally with a slight con- 

 striction where the septum comes (text-fig. 54, r.j>.}. 



Medullary rays are all uniseriate, and the cells composing 

 them are about one-half up to the same size in tangential 

 diameter as the adjacent tracheids. They appear conspicuous 

 in transverse section owing to the blackened contents which 

 lill many of them. In transverse section the end- walls are 

 placed at a rather variable angle. In radial section, as can 

 be seen in PI. XVII, fig. 1, the rays are principally two or thrn- 

 cells high, and the shape and angle of the walls vary considerably 

 (see also text-lig. 54), so that the cells arc rather irregular and 

 wavy in outline. 



Although otherwise the preservation of this fossil is good, the 

 medullary ray-cells do not show the pitting on their radial walls 

 in most cases. In one place, however, the pits can be very 

 clearly seen, and they are there round sharp-cut pits, two per 

 trachcid-field, one above the other (text-fig. 54, ;>.). 



The walls of the ray-cells, as petrified, seem to be very 

 delicately thickened, and the pits are not bordered. 1 have not 

 been able to detect any thickening or " abietinean pitting "on 

 the end-walls or other walls of the ray -cells. 



The pldoem elements are not well preserved, but those cells 

 of the soft tissue which are not crushed seem to be as large as 

 the tracheids. A few isolated stone-cells, and some stone-cells 

 with very thick walls in radial series, are to be seen. 



The cortex cells are largish, loosely arranged, and rounded 

 elements. There are no special features in the cortex visible in 

 the small portions of it which are preserved, except the large 

 resin-canals (PI. XVI, fig. 2, r.c.), of which the lining seems to 

 have consisted of several layers of flattened cells, but Is too 

 poorly preserved to show very clearly. 



AFFINITIES. The preservation of both pith and cortex in 



