164 Mr. E. Kidston on the Relationship 



originally slightly elevated cushion is converted into a circular 

 or oval depression. The point of attachment of the appen- 

 dicular organ in this example is in the centre of the upper 

 margin. This point represents the umbilicus of the older 

 scars. The part of the depression above the umbilicus on 

 older stems is therefore entirely caused by the pressure of the 

 base of the appendicular organ upon the bark. 



The leaf-scars are elongated - rhomboidal, and slightly 

 raised above the surface. Those of each series are connected 

 ■with each other by a flexuous ridge. The vascular bundle 

 dots are not shown, but the position of the vascular scar is 

 indicated by a little ridge. 



The bark at this age shows no traces of the longitudinal 

 clefts which are so characteristic of older examples. 



The full width of the stem at its lower portion is about 4 

 inches, and that this is its complete breadth is proved by the 

 impression of one of the Ulodendroid scars of the correspond- 

 ing opposite vertical row occurring in the matrix where part 

 of the stem has been removed. The surface of the bark 

 between the leaf-scars, at certain parts of the stem, is orna- 

 mented with fine ridges, though they are not present, or 

 only feebly so, on the small portion which forms the subject 

 of figure 2. 



Specimen No. 4. From Dalmeny, Linlithgowshire (Calci- 

 ferous Sandstone Series). Collected by Dr. Macfarlane. 

 PI. IV. fig. 3 (nat. size). — This specimen, which measures 

 about 6 by 4-^ inches, is preserved in a very fine-grained 

 bituminous oil shale. The leaf-scars are fusiform and slightly 

 elevated, those of the same series being connected with each 

 other by a slightly raised flexuous ridge. The surface of the 

 bark between the leaf-scars is beautifully ornamented with 

 fine, somewhat irregularly placed wavy lines. The vascular 

 scar is not clearly shown, but appears as a slightly raised 

 point towards the upper part of the leaf- scar. As the example 

 only shows one of the outer margins of the stem, its original 

 width cannot be ascertained. 



Specimen No. 5. From West Calder, Midlothian (Calci- 

 ferous Sandstone Series). PI. IV. fig. 4 (nat. size). — This 

 figure shows a small portion of an impression of a large stem^ 

 which is fully 2 feet long. The upper portion apparently 

 represents the complete breadth of the stem, which is 7 inches 

 across. The specimen shows no sign of any Ulodendroid 

 scar. The leaf-scars are elongated-rhomboidal or fusiform, 

 those in one series connected with each other by a ridge. 

 The vascular scar is situated towards the upper part of the 



