LEPIDODENDREAE. 209 



The second group of branches with Ulodendron character comes nearest 

 in surface-features to the Bergeria-forms with a deep-lying bundle-trace, 

 which were discussed above on p. 199, and which we have compared with 

 Dawson's Leptophloeum. To this group belong for example Ulodendron 

 majus and U. minus 1 , Stur's figures 2 which were classed by him with Lepi- 

 dodendron Veltheimianum but can scarcely belong to it, and a few drawings 

 of Carruthers 3 and Kidston 4 . The latter author refers all these forms with- 

 out hesitation to the genus Sigillaria, uniting them with the two species 

 Sigillaria Taylori, Carr. and S. discophora, Koenig. But the only reason 

 for this, as Zeiller 5 has well shown, is a certain resemblance in habit, a 

 resemblance which has misled Goldenberg 6 also into figuring a fragment 

 of Lepidophloios as Sigillaria Menardi. I do not know what it was that 

 decided Stur to place the two specimens mentioned above as resembling 

 Leptophloeum with Lepidodendron Veltheimianum. He found the shortly 

 lanceolate leaves still attached to one of them, and concluded from this 7 

 that it was a young stem and that the leaf-scars were not yet developed. 

 Even this conclusion appears to me to be thoroughly rash, considering the 

 little knowledge which we possess respecting the development of the leaf 

 and leaf-cushion. If Zeiller's view is right, and it still requires confirmation, 

 the Leptophloeum-forms which we are considering would have retained their 

 leaves a long time, and would have lost them at last by irregular fracture, 

 not by dismemberment. He mentions a piece of stem with excessively long 

 leaves from the mines of Lievin, in which the areolae of the broad bases of 

 the leaves were quite like those of Ulodendron majus. I have some pieces 

 in my possession which make me think it probable that Leptophloeum may 

 represent a distinct genus, though one nearly allied to Lepidodendron. But 

 much further research is needed for the clearing up of these questions. ' 



The last type of ulodendroid stems is represented by Lindley and 

 Hutton's 8 genus Bothrodendron, which though impugned by Kidston 9 has 

 been successfully defended by Zeiller 10 . The most clearly ascertained species 

 of the genus is Bothrodendron punctatum (Ulodendron Lindleyanum n ), 

 with large cups widely separated from one another, in which the scar is very 

 deep and very excentric. The surface of the stem is preserved in places 

 on the layer of coal which covers the casts, and is extremely characteristic. 

 It is marked by the very feeble development of the base of the leaf, and 

 as consequently there was no formation of cushions it is quite flat and 

 even, being furnished only with small sinuous longitudinal wrinkles. The 

 scars from which the leaves parted appear on it as small dots, separated 



1 Lindley and Hutton (1), vol. i, tt. 5, 6. 2 Stur (5), t. 22, ff. i, 2. * Camithers (11). 



4 Kidston (2), t. 4, f. 5 ; t. ?, ff. 8, 9; t. 7, f. 12. 5 Zeiller (11). Goldenberg (1), t. 7, f. I. 

 7 Stur (5), p. 288. Lindley and Hutton (1), tt. 80, 81. 9 Kidston (2). 10 Zeiller 



(11), t. 8. ll Steinberg, Graf von (1), t. 45, f. 4. 



P 



