62 ]Vrr. E,. Kidston on British Carlo?} iferoii ft Lj/copods. 



especially founding his opinion on the fact that Dawson 

 states in the description of his species — Lepidopliloios parvus 

 •= Sigillaria discophora — that the vascular points are obscure. 



I received, however, in 1886 from the Rev. David Lands- 

 borough, Kilmarnock, to whom I am indebted for many 

 instructive specimens of our Carboniferous Lycopods, a frag- 

 ment of a large specimen of Sigillaria discophora, which was 

 unfortunately broken into several pieces when removino; it 

 from the roof of the Whistler Seam, Kilmarnock. This 

 example shows clearly the central and two lateral cicatricules 

 of the leaf-scar. A small portion of the specimen is shown in 

 PI. IV. figs. 1, 1 a. This specimen conclusively proves that 

 the leaf-scars of Sigillaria discophora, Konig, sp. [^ U. minus, 

 L. & 11.), are provided with three cicatricules very similar to 

 those of Sigillaria, in whicli genus I believe the plant under 

 discussion should be placed. It is very remarkable that in 

 such a common British Coal-measure fossil the true outer 

 surface of the bark, showing the leaf-scars in a good state of 

 preservation, is so seldom met Avith. One reason for this is 

 the persistence of the leaves, Avhich appear to have retained 

 their attachment to the stem much longer than in the other 

 Coal- measure Lycopods, and it is not uncommon to find the 

 leaf-scars on stems of large specimens of Sigillaria disco- 

 jihora entirely obliterated by the foliage of the plant being 

 closely adpressed to the bark. 



I united U. majus and U. minus, L. & H. ; but M. Zeiller 

 regards them as distinct species, and has since figured a 

 specimen which he believes to be the U. majus of Lindley 

 and Hutton *, with which he unites Sigillaria [Lepidoden- 

 dron) discophora, Konig. From the examination of a plaster 

 cast of Konig's original specimen, which is still preserved in 

 the collection of the British Museum, I fet 1 quite satisfied 

 that Konig's plant is beyo2id all doubt referable to JJ. minus, 

 L. & H., and not to their U. majus, whatever may be the 

 claims of Vlodendron majus, L. & H., to rank as a species. 

 The size of the Ulodendroid scars or of the leaf-scars is of no 

 specific value, and I have specimens of Sigillaria discophora 

 in my own collection with Ulodendroid scars ranging up to 

 5^ inches in their greater diameter. There is no Uloden- 

 droid scar on the specimen of U. majus figured by Zeiller; 

 of course this does not prove that his specimen does not 

 belong to that species, but as the case stands, I at present 

 believe that U. majus, L. & H., and U. minus, L. & H., are 

 different ages and conditions of one species. I also feel cer- 



* ' Flore fossile du bassiu houiller tie Valenciennes,' p. 481, pi. Ixxiii. 

 fisr. 1. 



