166 Mr. R. Kidston on the Relationship 



blance to ordinary leaf-scars, as is well sliown in Sir Joseph 

 Hooker's plates of Leindostrohi *. This specimen, therefore, 

 does not, unfortunately, help us to decide whether stalked or 

 sessile cones were attached to the Ulodendroid scars. 



At fig. 1 1 a is shown, natural size, the small portion of the 

 stem marked a, fig. 11. This part is at a slightly lower level 

 than the rest of the outer surface of the fossil, and the leaf- 

 scars are slightly larger ; it is therefore probable that this 

 fragment of the specimen is not in its true position. 



This example shows no traces of longitudinal clefts in the 

 bark. 



Specimen No. 7. From Addiewell, Midlothian (Calciferous 

 Sandstone Series) . Collected by Dr. Macfarlane. — This 

 example, which is about 4 inches high and 4^ inches wide, 

 shows towards the left side of the fossil a Ulodendroid scar. 

 This is oval, and measures across the umbilicus about yV of 

 an inch. Its upper border is clearly defined, but the lower 

 portion of the scar, from the umbilicus downward, gradually 

 assumes the appearance of the ordinary leaf-scar- covered bark, 

 being clearly covered with broadly -fusiform leaf-scars, similar 

 in shape to those occurring on other parts of the stem and 

 belonging to the same spiral series. The leaf-scars on the upper 

 part of the Ulodendroid scar are, however, obliterated. 



Specimen No. 8. From Todholes, on the Bannoch-Burn, 

 about 5 miles S.W. of Stirling (Carboniferous Limestone 

 Series). — This specimen is the impression of a portion of an 

 old and much-cleft stem. The fossil measures about 11 

 inches in length and 8 in breadth. The main interest of 

 this example lies in the numerous ridges (the casts of the 

 clefts in the bark) which occur on its surface. Evidently 

 these ridges originally stood up at right angles to the 

 surface of the impression, but have been flattened or bent over 

 by subsequent pressure, and now hide the leaf-scars beneath 

 their extended surface. Some of these ridges have at different 

 parts of the fossil been broken off", and show that their line of 

 attachment to the fossil is comparatively small in proportion 

 to the superficial area they now in their flattened condition 

 present. As an instance, the width of one of these ridges 

 measures fully i% of an inch, but where it is broken ofi", the 

 line which represents the original width of the cleft, and on 

 which no leaf-scars are seen, only measures yo of an inch ; 

 the remaining y*^ inch of the flattened ridge is simply superin- 



* Memoirs of the Geol. Survey of Great Britain, vol. ii. pt. ii. p_. 440, 

 pis. iv., vii., & viii., 1848. (Kemarlis on the Structure and Affinities of 

 some Lepidostrohi.) 



