OF LOWER GREENSAND PLANTS. 277 



V. 5654. Small piece of petrified decorticated wood, now 

 measuring only 2-5x2x3 cm., and the pieces from 

 which the sections have been cut. In the largest 

 piece the central pith, growth-rings, vessels, etc., can 

 all be clearly seen with the naked eye. 



V. 5654 a. Figured, Stopes, Phil. Trans. Hoy. Soc. Lond., ser. B, 

 vol. 203, 1912, pi. vi, fig. 2; and text-fig. 82, ante. 

 Complete transverse section of above stem, showing 

 all the features described. In the centre two distinct 

 piths are to be seen, as a result of branching. 



V. 5654 b. Figured, Stopes, Phil. Trans. Roy. Soc. Lond., ser. B, 

 vol. 203, pi. viii, fig. 9 ; and text-fig. 83, ante. Trans- 

 verse section similar to the above, but showing the 

 pith still undivided. Locally this is rather better 

 preserved than the other sections, and the details 

 of vessels, wood-fibres, and medullary rays can all be 

 made out. On the right-hand side of the section are 

 the remains of another branch. 



V. 5654 C. Transverse section very similar to the above, showing 

 the pith of the smaller branch nearer to the axis than 

 in section a. 



V. 5654 d. Rather oblique tangential section of the above. The 

 details are poorly preserved, but the height of the 

 medullary rays can be made out. A small outgoing 

 branch is well preserved in transverse section. 



V. 5654 e. Figured, text-fig. 84. Radial longitudinal section 

 passing through the pith. Locally the medullary ray- 

 cells are fairly well preserved in radial section, and 

 show their much thickened walls and pitting. 



Lower Greensarid, Woburn ; Bedfordshire. 



Transferred from t7ie Botanical Dept., 1898. 



Genus HYTHIA, nov. 



As one species only of this type has been found, the species 

 and genus are not separately diagnosed. 



