242 DESCRIPTIVE CATALOGUE 



show very beautifully the different specialised cell- 

 types composing chains among the unspecialised cells 

 (text-fig. 67), though locally the pith is broken out. 



V. 2117 e. Longitudinal radial section of secondary wood just 

 touching the pith tangentially. 



V. 2117 f. Figured, text-fig. 70. Longitudinal radial section of 

 secondary wood showing the annual growths very 

 clearly, and also the resin -containing xylem-paren- 

 chyma, the tracheid-pits, and the outline of the 

 medullary ray-cells. 



V. 2117 g. Tangential longitudinal section, partly obliquely 

 radial. It is not well preserved, but the resin-con- 

 taining xylem-parcnchyma cells show up very clearly 

 in it. 



V. 2117 h. Figured, text-fig. 68. Longitudinal section partly 

 radial and partly tangential. It is locally very well 

 preserved, and shows in some places small leaf-traces 

 cut across in their exit, 



Lower Greensand ; Luccomb Chine, I. of Wight. 



Found and presented by Count Solms- Laubach, 1889. 



V. 5427. A small piece of branch 2-5 cm. in diameter, in two 

 fragments, from one of which sections have been cut ; 

 the other is 5 cm. long with a scrap of matrix adhering. 

 The centre of the stem is preserved with a number of 

 rings of woody growth, but none of the outer tissues. 

 The texture of the decorticated wood is partly visible, 

 but the petrifying medium is neither hard nor clear, 

 and the wood has rather the consistency of " lignite/' 



V. 5427 a. Transverse section of the above. Part of the pith 

 and the primary xylem are very well preserved. In 

 the secondary xylem the tracheids and medullary rays 

 are well preserved, and the feebleness of the differ- 

 entiation of the growth-rings is noticeable. 



V. 5427 b, C. Tangential sections of the above, showing the 

 height and frequency of the ray-cells. 



