LEPIDODENDREA E. 



199 



atum, Stbg, in which the entire leaf-trace of the scar is depicted, but this 

 is no doubt a mistake. Similar pictures are produced, when the rind of 

 coal remains in the mould of the surface 1 . The cast, stripped of this rind 

 and coinciding with the boundary between two layers of parenchyma of 

 different character, is in this case usually furnished only with small slightly 

 raised elongate-linear protuberances as indications of the leaf-bundles. 

 Casts of this kind are found in very extraordinary abundance. Casts are 

 described in Sternberg 2 as Bergeria, Presl (Fig. 19, B, C), the surface of 

 which agrees exactly with that of a Lepidodendron when deprived of its 

 epidermis ; some at least of these casts have belonged to a Lepidodendron, 

 as is seen from L. diplotegicides as reproduced by Schimper 3 after 

 Lesquereux 4 . They show raised rhombic cushions separated from one 



FIG. 19. Various states of preservation of the surface of the stem of Lepidodendron. A Lepidodendron obovatum, 

 to some extent improved and diagrammatically represented ; on the right side the surface in the mould, on the left 

 the Aspidiaria-state, the latter introduced from other specimens ; above the rhombic scar of separation of the leaf are 

 seen the two trace-scars one above the other. B and C Bergeria-states. B Bergeria angulata, C Lepidodendron 

 nothum, Ung., from Australia. D single leaf-cushion of the cast of a Lepidodendron, a diagrammatic representation 

 showing the different traces and marks. A and C after O. Feistmantel 5 , B after Sternberg s , D after Stur 7 . 



I 



another by narrow intervals ; the bundle-trace is seen as a depression at 

 the point of highest elevation. In the examples of this state of preservation 

 figured in Sternberg the emergence of the vascular bundle is extremely 

 close to the upper angle of the area of the cushion ; the difference in size 

 between the upper and lower faces in these forms must have been very 

 pronounced (Fig. 19, B}. At the same time the two diagonals of the cushion 

 are of nearly the same length, its outline approaching the form of a 

 square. To this group undoubtedly belong several remains figured by 

 Schmalhausen 8 from the Ursa zone of Bear Island in Siberia, and also Lepi- 

 dodendron tetragonum from the Coal-measures of Saxony 9 . O. Feist- 

 mantel's 10 remarks on this point should be referred to ; this author considers 

 Bergeriae to be states of preservation both of Lepidodendron and of the 

 genus Lepidophloios which will be noticed presently, and he may be quite 



1 Goppert (19), t. 39, f. 2. 2 Sternberg, Graf von (1), t. 63, ff. 16-19. 3 Schimper (1), 



t. 60, f. 7. * Lesquereux (1). 5 Feistmantel (1), III. 6 Sternberg, Graf von (1). 



7 Stur (5). 8 Schmalhausen (3), t. 2, f. 5. 9 Geinitz (8), t. 3, ff. I, 2, and Schimper (1), 



t. 60, ff. 9, 10. 1H O. Feistmantel (3), p. 200. 



