HrrHERTO KNOWN AS STEKNBBRGI^. 355 



species, which is doubtful; it affords demonstrative evidence 

 that the trees have been branched in the same way as the 

 ordinary gymnospermous exogens. 



The collection of Mr. Binney contains some fine por- 

 tions of large coniferous trees. Some of these have had 

 remarkably thick piths, besides which their pleurenchyma 

 exhibits the same structure as that which I have delineated 

 in fig. 7 . It appears very probable, that not only these have 

 belonged to the same plant, but that the entire group of coni- 

 fera3 from the coal-measures, constituting M. Brongniart's 

 genus Dadoxylon, are the ligneous portions of the trees of the 

 piths of which Sternbergla approximata represents internal 

 casts. 



With the foliage of these trees we are as yet unacquainted ; 

 we can scarcely regard it probable that all traces of it have 

 disappeared, if we bear in mind the comparative frequency 

 with which portions of stems and branches are met with. 

 The foliage of true coniferous plants is of frequent occur- 

 rence in the oolitic shales and sandstones of the Yorkshire 

 coast ; consequently, there is no reason why they should not 

 also have been preserved in the similar strata of the caiboni- 

 ferous epoch. It is possible that the foleaceous appendages 

 of Dadoxylon may be represented by some of the well-known 

 plants of the coal-measures, which have hitherto been con- 

 founded with Lepidodendron. The beautiful coniferous 

 plants from Yorkshire, of which Lycopodites Williamsonis 

 is the great type, were for many years regarded even by 

 Brongniart as belonging to the Lycopodeaceae, There is 

 therefore nothing improbable in the supposition, that phyto- 

 logists may have fallen into a similar mistake respecting 

 those of the coal-measures. The young shoots of many 

 conifene are covered with elongated markings closely re- 

 sembling those of a Lepidodendron ; consequently we 

 might expect that the external bark of the young twigs of 

 Dadoxylon would be sculptured in the same way. If so, 



