OF THE FOSSIL PLANTS OF THE COAL-MEASURES. 
67 
of the Owens College, and found in one of the upper coal-shales of Lancashire. 
The figure is reduced to two thirds the size of the original. It is not without signi- 
ficance that the only vegetable remains seen in the same large slab are an abundance of 
leaf-bearing stems and twigs of Asterophyllites of various sizes, which appear to be in 
all respects facsimiles of those described in the preceding pages. This example of the 
stem consists of a number of well-marked internodes of various sizes. These are marked 
by numerous faintly defined parallel longitudinal grooves, with others of a much more 
sharply defined character at irregular intervals. The latter have obviously been cracks 
in the original bark, into which the matrix has entered, causing the latter to stand 
out in projecting ridges. In this specimen the large cicatrices are planted in a verticil- 
late manner upon each third node ; in another and otherwise similar specimen in the 
Owens College collection they are only planted upon every eighth node, thus exhibiting 
variations in this plant which may possibly have been specific ones. The latter specimen 
further indicates what is but obscurely shown in the example figured, viz. that the 
cicatrices appear as if planted uypon the node, and not above or below it. 
The general resemblance of these large stems to Plate VII. fig. 44 is very striking. 
The facts now stated, combined with the difficulty of collocating these examples with 
any other known plant, strongly incline me to the belief that they are the arborescent 
stems of the Asterophyllites with which they are associated in the specimen figured. 
In August 1869 I published in the ‘Monthly Microscopic Journal’ the brief memoir 
referred to in No. IV.* of the present series, in which I separated two very distinct groups 
of plants which had hitherto been regarded as allied to each other, viz. those belonging 
to Endlicher’s genus Dadoxylon , whose wood-cells were truly discigerous, and those 
in which this character was only apparent, not real, it being due to a mere modification of 
fibro-vascular tissue. In that memoir I said : — “ It appears necessary, therefore, to esta- 
blish a new genus for all the plants whose woody tissues consist of reticulated fibres, 
and the name of Dictyoxylon appears an appropriate one for it. I should propose, for 
the present, to include in this genus all the reticulated types. At some future time 
their further separation into two or more genera may be requisite ”f. When giving a 
sketch of this new genus at the Edinburgh Meeting of the British Association, I 
included in it, in accordance with the above determination, a new plant from the Coal- 
measures, to which I assigned the name of Dictyoxylon radicans. But in working out 
the details of the genus for the fourth memoir of the present series, I found that the 
necessity for further generic subdivision which I had anticipated was already urgent. 
In a letter to Dr. SharpetJ, I observed, respecting the D. radicans : — “ I think it not im- 
probable that this has been the subterranean axis of some other plant, since I have 
succeeded in tracing its ultimate subdivisions into rootlets. I propose for the present 
to recognize it by the generic name of Amyelon. My specimens of this plant are very 
* Philosophical Transactions, 1873, p. 378. 
+ Proceedings of the Royal Society, vol. xx. p. 436. 
K 2 
f Loc. cit, p. 68. 
