276 



DESCRIPTIVE CATALOGUE 



A few of the elements immediately adjacent to the vessels 

 appear to be parenchymatous and show contents. 



Slight differences in shape, such as are illustrated in text- 

 fig. 84, seem to be the only variations in the cells of the 

 medullary rays. In transverse section their radial extension is 

 generally small, only half as much again as their tangential 

 diameter ; in many cases this is less, and the cells are practically 

 square. Their end-walls are nearly straight or at a slight 

 angle, and even in the transverse section the heavy thickening 

 and pitting of all the wails can be made out. Typical cells are 

 illustrated at?n., text-fig. 84, where the end-walls are to be seen 

 with well-marked thickenings and pittings of the type described 



m. 



Text-fig. 84. Salidia Scoff ii, Stopes. Radial section showing the shape 

 of a few of the ray-cells, with details of their pitting, m. Thickening 

 and pitting of end -walls, a., similar in type to the " abietinean pitting " 

 of Conifers. No. V. 5654 c . 



as " abietinean " when found in Gymnosperms. In a few of the 

 cells there are indications of oval or round pittings of a larger 

 size on the radial walls. 



AFFINITIES. As was the case when I first described this 

 specimen (Stopes, 1912), I do not feel in a position to draw any 

 useful comparison between it and the woods of any definite 

 living genus. Every detail of its structure is characteristic of 

 the higher groups of woody Dicotyledons. The lack of " primi- 

 tive" features in so early a plant is the chief interest of the 

 specimen. 



