530 



Description of Specimens. 



Mesembrioxylon, ^sp. 



Moorlands A (figs. 1, 2). 



The state of preservation is good. The lumen of the 

 tracheide is not obscured by brownish matter nor do the rays 

 contain any dark-brown substance. 



Growth rings are clear. 



Bordered pits uniseriate, separate, and circular (fig. 1). 



Medullary rays uniseriate, two or three cells high, occa- 

 sionally four or five. The cells are free from dark- 



(2/ 



Fig. 4. 



Mesembrioxylon, sp. Yalloum A. Radial 



section showing pits in the field and 



tracheal pitting. x275. 



brown contents. There may be one or two oval, oblique, 

 apparently simple pits in the field (fig. 2). The presence of 

 pits on the horizontal and tangential walls of the rays is well 

 known to be a difiicult character to determine, (^) and negative 



(4) Seward, vol. iv., p. 169. 



