232 LEP1DOQENDREAE. 



decortication. But apart from this, I cannot think it allowable to bring 

 contradictory statements of this kind into agreement with one another by 

 means of conciliatory hypotheses without fresh investigation. It is my 

 opinion that we ought not at present to hold either to Binney only or only 

 to Williamson ; the older publication by Dawes, which was excellent in its 

 time, cannot now be taken into consideration. I have myself no doubt as 

 to which of the two first authors deserves the greater confidence. Binney 

 is dead, and his original specimens have been for a long time inaccessible : 

 whenever the opportunity comes for submitting them to fresh examination, 

 it will be possible finally to settle this question ; and then his Haloniae also 

 will ultimately show the two kinds of trace-bundles, which, as he says him- 

 self in the Introduction, may not have been brought out with the necessary 

 distinctness by the entirely unprejudiced draughtsmen. A few words must 

 be added in conclusion about Ulodendron. Carruthers l and Williamson 2 

 have stated a few facts only respecting its inner structure, which is said to 

 be essentially that of Lepidodendron Harcourtii. But I confess that I am 

 not perfectly satisfied with regard to the determination of Williamson's 

 specimens, for he encountered on the tangential section 3 transversely 

 rhombic leaf-cushions, such as occur in Lepidophloios but not in Uloden- 

 dron ; and leaf-bases are figured in the radial section 4 , which also remind 

 us rather of Lepidophloios. It is true that the great cone-scars are said to 

 be in the usual two-rowed position in the specimen ; unfortunately no figure 

 of the surface is given. 



The fructifications only remain to be considered. These have long 

 been known as cone-like extremities of shoots close set with spirally 

 arranged sporangiferous leaves, the connection of which with indubitable 

 branches of Lepidodendron has been so clearly established in particular 

 cases, that the true nature even of such specimens as have not been met 

 with in the same close connection cannot usually be disputed. Still figures 

 proving this are not common in the literature ; those of Stur 6 , Lesquereux 6 

 and Brongniart 7 may be named as the most important. Further confirma- 

 tion is obtained from the results of the anatomical investigation of the axes 

 of petrified specimens, which show the essential points of the structure of 

 the shoots of Lepidodendron. These cones, usually known by the collective 

 name of Lepidostrobus, are everywhere abundant on heaps of refuse coal in 

 the form of impressions ; they occur here and there as petrifactions in the 

 English calcareous nodules, and in certain sphaerosiderites from the neigh- 

 bourhood of Wolverhampton. Few silicified specimens are known, but in 

 these the inner structure is wonderfully well preserved. 



1 Carruthers (13). " Williamson (1), II, p. 209; tt. 26, 27. 3 Williamson (1), II, t. 28, 



f. 28. * Williamson (1), II, t. 28, f. 27. 5 Stur (5); t. 19, f. 9. e Lesquereux (1), vol. iii, 



t. 107, f. 2. 7 Brongniart (1), vol. ii, t. 24, f. 5 and t. 25, f. 2. 



