302 



DESCRIPTIVE CATALOGUE 



sometimes single rows separated by medullary rays, sometimes 

 as many as 4 or 5 tracheid-rows adjacent (text-fig. 96). 



The tracheids are squarish or oblong, measuring up to about 

 30-40 /x in diameter (text-fig. 1)6). In longitudinal direction 

 they are still more opaque, but in a few cases bordered pita 



Text-fig. 94. Cycadeoidta Yatctii, Carr. End of a specimen broken across 

 showing the two rings of wood, j-,, A\,. and tho wide pith-cast with 

 ridged inner surface, /.; /., leaf-based. .Nat size. No. 47049. 



(circular) can be seen. The two rows of bordered pits described 

 by Carruthers are sometimes present. 



Between the wood-rings and outside the second wood-ring 

 are zones of different tissue about 2-2'omm. in thickness. This 



