On Fossil Plants from the Coal of Lancashire, tyc. 129 



gans comparee a celle des Lepidodendron et des Stigmaria et a celle 

 des vegetaux vivants," in the Archives du Museum d'Histoire 

 Naturelle. His specimen of Sigillaria elegans was in very perfect 

 preservation, and showed its external characters and internal struc- 

 ture in every portion except the pith and a hroad part of the plant 

 intervening betwixt the internal and external radiating cylinders. 

 Up to this time nothing had been seen at all to be compared to 

 M. Brongniart's specimen, and no person could have been better 

 selected to describe and illustrate it. His memoir will always be 

 considered one of the most valuable ever contributed on the fossil 

 flora of the Carboniferous period. 



In 1849, August Joseph Corda published his ' Beitrage zur Flora 

 der Vorwelt,' a work of great labour and research. Amongst his 

 numerous specimens, he describes and illustrates one of Diploxylon 

 cycadeoideum, which, although not to be compared to M. Bron- 

 gniart's specimen, still affords us valuable information, confirming 

 some of that author's views rather than affording much more original 

 information. All these last three specimens M. Brongniart, in his 

 ' Tableau de vegetaux fossiles consideres sous le point de vue de leur 

 classification botanique et de leur distribution geologique' (published 

 in 1847), classes as Dicotyledones gymnospermes, under the family 

 of Sigillurees — amongst other plants his Sigillaria elegans, Mr. 

 Witham's Anabathra, and Corda's Diploxylon. 



In 1862 the author published, in the 'Quarterly Journal of the 

 Geological Society ' of that year, an account of specimens which 

 confirmed the views of the three learned authors above named as 

 to Sigillaria and Diploxylon being allied plants ; but showed that 

 their supposed pith or central axis was not composed of cellular 

 tissue, but of different-sized vessels arranged without order, having 

 their sides barred by transverse striae like the internal vascular 

 cylinders of Sigillaria and Lepidodendron. These specimens were 

 in very perfect preservation, and showed the external as well as the 

 internal characters of the plants. 



All the above specimens were of comparatively small size, with 

 the exception of that described by M. Corda, which, although it 

 showed the external characters in a decorticated state, did not 

 exhibit any outward resemblance to a plant allied to Sigillaria with 

 large ribs and deep furrows so commonly met with in our coal-fields, 

 but rather to plants allied to Sigillaria elegans and Lepidodendron. 



In the present communication the author has described some speci- 

 mens of larger size than those previously alluded to, and endeavoured 

 to show that the Sigillaria vascularis with rhomboidal scars gradu- 

 ally passes as it grows older into a ribbed and furrowed Sigillaria, and 

 that this singular plant not only possesses two woody cylinders 

 arranged i u radiating series, an internal and an external one divided 

 by a zone of cellular tissue, both increasing on their outsidcs at the 

 same time, but likewise has a central axis composed of hexagonal 

 vessels, arranged without order, having all their sides marked with 

 transverse strise. Evidence is also adduced to show that Sigillaria 

 dichotomizes in its branches something like Lepidodendron, and that, 



