110 



DESCRIPTIVE CATALOGUE 



of these tj'loses is seen in text-fig. 26, t. As may be judged from, 

 the photographs and drawings, the walls of the tyloses are of a 

 rather unusually firm appearance, which may possibly be corre- 

 lated with the fact that the epithelium from which they arise is 



Text-fig. 27. Pityoxylon Benstedi,sp.nov. Longitudinal section, showing 

 tracheid-pittinga, tr. Two medullary rays illustrate the various types 

 of cell comprising the ray. rt., ray-tracheids ; p., ray-cells with large 

 pits; a., typical "abietinean pitting" of end-walls of medullary ray- 

 cells. No. ;J8353 B/ 



