47 
Wcas, and it appears still is, endorsed by Mr. Binney. After 
thus endorsing what I believe to be a grave mistake, Mr. 
Binney proceeds to justify his doing so by appealing to a 
specimen which I have not seen, but which Mr. Binney ’s own 
description convinces me is a plant altogether different, alike 
from THE Stigmaria of authors, and from M. Goeppert’s and 
Mr. Binney s own figures. Mr. Binney describes his new spe- 
cimen as having a radiating woody cylinder, immediately 
within which is a second series of large vessels not arranged 
in radiating wedges, and which Mr. Binney says is “some- 
thing like a medullary sheath, enclosing a medulla composed 
of very small and short barred tubes or utricles, in which 
are mingled large vascular tubes or utricles.” Though this 
use of vague terms renders the sense obscure, I pre- 
sume that Mr. Binney simply means that in the medulla of 
his plant a vasculo.T cylinder encloses a cellular medulla, or, 
in other words, that his specimen has a Biploxyloid axis. 
That Mr. Binney possesses a specimen having the above 
structure, and giving off rootlets from its periphery, I 
have no reason for doubting, since in the Memoirs already 
quoted I have described a similar structure under the 
name of Diploxylon Stigmarioideum, and respecting which 
I make the following observations: — “It is possible that 
the plant may, like Stigmaria, prove to be the upper- 
most part of a root of some of the other forms” {i.e. of 
Lepidodendroid stems), “though I have never yet found 
it associated with any rootlets, and it may be a fragment 
from the base where stem and roots united.” — (loc. cit. p. 
239.) I arrived at the above conclusions becanse I found in 
the specimen described evidence that large rootlet bundles 
were given off from the woody zone as in rhe true Stig- 
maria. But I affirm that out of hundreds of Stiofinarian frao-- 
ments that I have examined, I have only found two possess - 
ing this structure; and I unhesitatingly express my conviction 
that Mr. Binney’s specimen is another example of an equall}" 
rare type, both being entirely distinct from Stigmaria ffcoides. 
