ME. E. W. BINNEY ON SOME LOWER-COAL-SEAM EOSSIL PLANTS. 
593 
Lepidodendron.” It is singular that Drs. Lindley and Hooker, as well as such acute 
observers as Brongniart and Goeppert, had not noticed this line of division, but it was 
no doubt owing to the imperfect specimens which they had examined. After the 
discovery of the outer radiating cylinder by Witham in Lepidodendron , and the same 
arrangement in Sigillaria by Brongniart, it was to be expected that such outer radia- 
ting cylinder would be found to occur in Stigmaria , if it were the root of Sigillaria. 
After an inspection of a great number of specimens, the cabinet of Mr. Bussell, of 
Chapel Hall, Airdrie, has afforded me four or five distinct specimens which give clear 
evidence of the existence of this outer radiating cylinder in Stigmaria. They are all in 
clay ironstone, and have not been much compressed. He has kindly allowed me to 
slice two of the specimens, which afford decisive evidence of the former existence of 
both an inner and an outer radiating cylinder. The space on the outside of the inner 
cylinder does not distinctly show the bundles of vessels communicating with the root- 
lets, although there is some evidence of their former occurrence. The bell-shaped 
orifices from which the rootlets spring are well displayed, and the space between them 
is occupied by wedge-shaped masses of tubes or elongated utricles arranged in radiating 
series, and not to be distinguished in any way from those shown in Plate XXXY. fig. 5. 
Indeed the transverse section of the specimen there figured would almost do for a 
representation of the Stigmaria if the latter had the central axis preserved, which it 
unfortunately has not. There is the same internal radiating cylinder, the same space 
occupied by lax cellular tissue, which gradually passes into tubes or elongated utricles 
arranged in radiating series, apparently diverging from circular openings, and parted by 
large bundles of muriform tissue containing vessels barred on all their sides, extending 
to the outer bark. The accompanying woodcut (fig. 4) will give a much better idea of 
its structure than any laboured description. 
Fig. 4. 
This specimen clearly proves, by the evidence of internal structure alone, that Stig- 
maria is the root of Sigillaria , each of them having an inner radiating cylinder com- 
