6 PAL^ONTOLOGICAL BOTANY. 



either side. Farther up the markings are smaller in size, 



FiR. 3. 



obliquely quadrilateral, and present circular dots along the 

 boundary lines chiefly (Fig. 4). Higher still the quadrilateral 



Fig. 4. 



form becomes more apparent, and the dots disappear (Fig. 5). 

 The epiphloeum thus presents differences in its markings 

 at different heights on the stem. 



The part of the bark immediately below the epiphlceum is 

 well developed, and is of a spongy consistence. When 

 examined microscopically it is seen to be composed of cells of 

 Figs. 3, 4, and 5. Markings on Araucaria bark. 



