4 ST1GMARIA F1C0IDES. 



' Fossil Flora of Great Britain.' 1 The former of these sections (loc. cit., fig. 1) is, as 

 far as it goes, a fair representative of such sections of the plant ; but the other, 

 fig. 2, is wholly unintelligible to me. A much more accurate use of the same 

 specimen was made by Professor Prestwich himself who figured and described 

 additional sections of it in his classical memoir on the ' Geology of Colebrook Dale.' 2 

 He was indebted to the late Robert Brown for the accurate suggestion that certain 

 vascular bundles, springing from the vascular axis figured, terminated at the 

 depressed external tubercles so characteristic of all specimens of Stigmaria. The 

 existence of these bundles had escaped the notice of the authors of the ' Fossil 

 Flora,' though they certainly ought to have represented them in their fig. 2, as 

 they were illustrated in corresponding sections in Professor Prestwich' s memoir. 



A memoir ' On Some Peculiarities in the Structure of Stigmaria,' by Sir Joseph 

 Hooker, appeared in 1848 . 3 The author, in this memoir, recorded all that was then 

 known about Stigmaria. But at that time illustrative materials were few, and 

 too often inconclusive. Some equally imperfect specimens previously described 

 by Professor Goppert 4 misled Dr. Hooker as to the origin of the vascular bundles 

 noticed by Robert Brown, as they afterwards misled Mr. Binney. In 1858 the 

 latter author figured and described the central portion of a Stigmarian rootlet, 5 

 and in a second memoir 6 he republished the same figure, and along with it he 

 represented the fragment, from the interior of which his section of the rootlet had 

 been obtained. This fragment was misinterpreted by Binney exactly as a similar 

 specimen had previously been by Goppert. 



Parts II and XI of my memoirs on the " Organisation of the Fossil Plants of the 

 Coal-Measures " 7 contain some hitherto undescribecl features in the structure of 

 Stigmaria, as well as diagrammatic restorations both of that structure and of the 

 organic relations of the root to its Lepidodendroid and Sigillarian stems ; those 

 restorations need little, if any, alteration to adapt them to the present state of our 

 knowledge, though during the subsequent years a large amount of information 

 has been obtained respecting the details of the organisation of Stigmaria. 



On examining the trees discovered at Dixon Fold, it soon became obvious that 

 the shaly materials of which they were composed would give way, however care- 

 fully they might be protected from the weather. Hence an Italian artist named 



1 Vol. iv, p. 166. 



2 ' Transactions of the Geological Society of London,' 2nd series, vol. v, PI. 38. 



3 ' Memoirs of the Geological Survey of Great Britain and of the Museum of Practical Geology 

 in London,' vol. ii, part 2, 1848. 



1 ' Les Genres des Plantes Fossiles.' Bonn, 1841. 



5 ' Quarterly Journal Geol. Soc.,' vol. xv, p. 76. 



6 ' Observations on the Structure of Fossil Plants found in the Carboniferous Strata,' part iv, 

 " Sigillaria and Stigmaria," Palseontographical Society's vol. for 1875. 



7 ' Phil. Trans.,' 1872 and 1881. ' 



