FROM THE HUTTON COLLECTION. 97 



will give a general idea of the fructification, leaves, branchlets, 

 branches, and leaf-scars of this species, and the synonyms quoted 

 above, which are only a few of the best known from the oldest 

 authors, shew how difficult it is to decipher, without error, the 

 remains of one of the best known fossils of tbe Coal-measures. 



Sternberg included in his Lepidodendron dichotomum, tbree 

 species and genera of plants, viz., Lep. Sternhergii, Brongt. (t. 1), 

 Lepidophloios laricinus=.Lep. acerosum, L. et H. (t. 2), and Lepi- 

 dodendron longifolium (t. 3), which is, in this Catalogue, referred 

 to Knorria longifolia, Stb. sp. The name dichotomum was in itself 

 objectionable, and became more so from including several species, 

 so that Brongniart was fully justified in altering Sternberg's 

 name for this species. 



The Type-specimens of Lepid. dilatatuin, L. et H., P. P., pi. 7, 

 f. 2, and of Lepid. elegans, L. et H., P. P., pi. 118, are in the 

 Collection of the Natural History Society, and these represent 

 very characteristic portions of L. Sternhergii. The Lindley- 

 Hutton figure, P. P., pi. 4, is, I think, a little improved in the 

 shape of the leaf-scars, but their Plate 9 is a good representation 

 of the branchlets of this plant. Plate 19 bis gives a good idea 

 of the compressed leaf-cushions and leaf-scars of an old stem. 

 Plates 112, 199 shew the leaf-scars and -cushions of large and 

 small branches. Plate 203 gives a correct appearance of the 

 stem of this tree, as it may often be seen on the shale roof of the 

 Bensham seam in the Jarrow and Hebburn district. The stem 

 of the Possil tree figured in the P. P., pi. 54, and referred to 

 Sigillaria pachy derma, Bt., is, I think, from careful examination 

 of part of it still preserved in the Museum of the Natural History 

 Society, a cast of the stem of this Lepidodendron. Recently, 

 when it was mounted in its present position a section of the 

 medullary cavity, surrounded with a ring of carbonaceous matter 

 like that which is often seen in Stigmaria, was observed to 

 traverse the whole length of the stem, and as this pith differs 

 essentially in character from the pith of Sigillariaz={Endogenites 

 striata, L. et H.), as observed in a specimen of Sigllaria reniformis, 

 Bt., and as the ribs on the cast are not continuous as in the 

 latter genus, but only partial and false, it is necessary to conclude 



