OF LOWER GBEEXSAND PLAKTS. 177 



rings of growth. On one side a small branch is being 

 given off. The dark silicified medium preserves the 

 tissues well. 



V. 13193 a. Figured, PI. XV, figs. 2 & 3. Transverse section of 

 the above stem showing part of the pith and primary 

 xylem well preserved. The general character of the 

 wood, with the numerous dark resin-parenchyma ceils, 

 is well seen (PI. XV, fig. 2). The " composite" zones 

 of autumn wood are also well seen in this section 

 (PI. XV, fig. 3). Extending about halfway round 

 the outer part, of the eighth growth-ring is a long line 

 of traumatic resin-canals, as well as several other 

 groups of resin-canals just outside the outgoing 

 branch. The presence of such resin has not been 

 described for this type of wood before. 



V. 13193 b. Longitudinal tangential section of the above stem. 

 The section is well preserved, and the distribution of 

 the low small medullary rays can be well seen. 



V 13193 C. Longitudinal radial section of the above stem. 

 The size and arrangement of the ray-cells can be very 

 well seen, and their radial pits can be made out, 

 though they are not very clear. The distribution and 

 character of the resin-containing parenchyma arc well 

 shown. The large traumatic resin-canals appear in 

 several places in the section. 



Lower Greensand ; Luccomb Chine, Isle of Wight. 



Found and presented by Dr. M. C. Slopes, 1912. 



V. 13192, V. 13192 a, b, & c. Specimen consisting of a small 

 part of the base of a forking branch, just where the 

 branches are separating. The wood is clean of matrix 

 and is waterworn. Tho tissues are well petrified in a 

 dark silicified medium. 



V. 13192 a. Figured, PI. XV, fig. 1. A transverse section of the 

 central part of one axis and the outgoing branch, 

 the area of the section being about 3 x 3'8 cm. In the 



N 



