162 Mr. K. Kidston on the Relationship 



in different stations ? These questions are equally curious 

 and interesting to solve. 



I have had the Phcenicurus in abundance at the Laboratoire 

 Arago. My boat, every time it went out to seek specimens 

 of Tethys lor me, brought me a great number of all sizes, 

 free or fixed. I hope, therefore, shortly to elucidate this still 

 obscure history. 



XVIII. — On the Relationship of Ulodendron, Lindley and 

 Hutton^ toLepidodendron, Sternberg ; Bothrodendron,Z/^nc^Ze3/ 

 and Hutton ; Sigillaria, Brongyiiart ; and Rhytidodendron, 

 Boulay. By Robert Kidston, F.G.S. 

 [Plates 1II.-VII.] 

 [Continued from page 139.] 



II. Desceiptions of Specimens. 

 Lepidodendron Veltheimianum^ Sternberg. 



Specimen No. 1. From Burghlee Pit, Loanhead, Midlothian 

 (Carboniferous Limestone Series). PI. Ill, fig. 1 (nat. size). 

 ■ — This fossil, which is represented by an impression of the 

 plant in a fine-grained micaceous sandstone, is 1 5 inches long 

 and at its broadest part about 4| inches wide. Towards its 

 upper part it shows one of the characteristic Ulodendroid 

 scars, which is 4| inches high and 2^ inches wide. The 

 central umbilicus is situated about 2 inches above the lower 

 margin of the scar. On the lower surface of the Ulodendroid 

 scar, and extending slightly above and around its umbilicus, 

 are rows of little " dots " arranged in spirals, converging 

 towards the umbilicus. The little " dots " indicate the posi- 

 tion of the vascular bundles of the aborted leaves, and become 

 closer to each other as they approach the umbilicus. On the 

 upper part of the scar is a number of straight lines which 

 radiate from the umbilicus ; these are the impressions of the 

 basal leaves or bracts of the appendicular organ. The um- 

 bilicus is slightly raised. On other parts of the specimen 

 are seen the impressions of the leaf-scars, which are, in form 

 and arrangement, similar to those of Lepidodendron Velt- 

 heimianum. To the left of the fossil the leaf-scars are 

 obliterated by a longitudinal splitting of the bark. 



As the specimen is only an impression it must be remem- 

 bered that the elevations on the fossil were depressions in the 

 plant. 



