106 PROCEEDINGS OP THE GEOLOGICAL SOCIETY. [Jan. 8, 



Fig. 7. Fterichthys macrocephalus, Egerton. Dorsal aspect. In the ' o «<h S^ 

 Collection of Mr. T. Baxter, F.G.S. I ^ o § 



Fig. 8. Ventral aspect. The head is wanting. In Mr. G. E. I ^^ § ^ 



Eoberts's Collection. '^ ~ 



Fig. 9. Impression of the anterior ventral and thoracic plates and 



of a part of one limb. In Mr. Weaver Jones's Collection. 



(All the figures are of the natural size.) 





2. On some Fossil Plants, showing Structure, /rom the Lower Coal- 

 Measures of Lancashire. By E. W. Binney, Esq., F.E.S., F.G.S. 



[Plates IV. V. VI.] 



Of aU the fossil plants found in the Coal-measures, probably none 

 is more widely diffused, or its whole internal structure considered to 

 be better known, than the genus Lepidodendron. The investi- 

 gations of Messrs. Witham, Lindley and Hutton, Corda, Brongniart, 

 and J. D. Hooker appeared to have almost exhausted the subject, 

 so far as the structure of the stem was concerned. Dr. Hooker, 

 after describing the double system of vessels in Stigmaria, first shown 

 by Goeppert, and the consequent approach in this respect to the 

 Diploxylon of Corda, says — " In Lepidodendron, again, there is the 

 same double vascular system ; but that from which the bundles arise, 

 which proceed to the leaves, is placed externally to the wood, where 

 it formed a continuous zone with a well-defined inner edge (in juxta- 

 position with the outer circumference of the inner zone) and a sinuous 

 outer edge from which the diverging bundles are given off."* He, 

 as well as all the other authors before named, considered the pith of 

 Lepidodendron to be composed of cellular tissue, and that it was 

 surrounded by a zone of large barred vessels, of hexagonal shape, 

 which was succeeded by a narrow circle of lesser hexagonal vessels, 

 also barred on their sides. Then came the great mass of cellular 

 tissue containing the bundles of vessels which traversed it, leading 

 from the outer vascular cylinder to the leaves. This was succeeded 

 by a radiated series of elongated utricles forming the outer bark of 

 the tree. The whole of the structure, as above described, was clearly 

 proved by the specimens of Mr. Witham to belong to Lepidodendron 

 Harcourtii. Corda proved Protopteris Oottonea to have the same 

 structure ; and Mr. Dawes, of Smethwick, near Birmingham, pos- 

 sesses in his cabinet most beautiful specimens which fuUy confirm 

 the above views, and especially with respect to the pith being en- 

 tirely composed of cellular tissue. 



The specimens intended to be described in this communication 

 show that fossil plants having all the external characters of Lepi- 

 dodendron have a pith, if it may be so called, or, more properly 

 speaking, a central axis, composed not of cellular tissue, but of very 

 large hexagonal vessels (a) mixed with smaller ones, both having all 

 their sides barred with transverse striae. This is succeeded by 



* Memoirs of the Geological Survey of Great Britain, vol. ii. part ii. p. 435. 



