932 PROF. F. E. WEISS ON A BISERIATE HALONIAL 
tubercle (Pl. 26, fig. 17). This middle cortex is of the same nature as that of the main 
axis, but is remarkable for the great distinctness of the two kinds of cells deseribed above, 
the smaller denser ones accompanying the stelar branch very much in the same way as 
they do the leaf-traces (see Pl. 26. fig. 16). In one or two places I have observed at 
the demarcation between the middle and the outer cortex a group of cells of the former 
showing an arrangement which indicated a certain amount of meristematic activity ot 
the outermost part of the middle cortex. A similar phenomenon I have described (1901) 
in a rootlet which I consider belonged probably to Lepidophloios fuliginosus. 
Whether or not the stelar branch supplied a strobilus cannot be determined from the 
present specimen. I have, however, pointed out above one or two points in which it 
diverges from the structure described for the peduncles of various lepidodendroid 
strobili. 
The anatomical characters of the main axis, however, as described above leave, I 
think, no room for doubt that this halonial branch belonged to the plant now known as 
Lepidophloios fuliginosus. 
The most important points in the structure of the halonial branch which support this 
identification are :— À 
(1) The parenehymatous pith and the general arrangement of the primary xylem. 
(2) The very characteristic mode of secondary growth resulting in the almost exclusive 
formation of parenchymatous cells. 
(3) The well-preserved middle cortex and its peculiar structure. 
(4) The secretory tissue of the outer cortex. 
These special points in which the plant differs from one or other of the various 
Lepidodendracee are, I think, sufficiently characteristic to confirm the identification 
made by Dr. Scott (1898). 
On anatomical grounds, then, we may describe the specimen under consideration 
as a branch of Lepidophloios fuliginosus. The halonial branches of this species are 
generally of the multiseriate type, 7. e. with a quincuncial arrangement of the tubercles. 
I have, however, pointed out in the first part of this paper that this was by no means 
always the case. Williamson has described specimens of Lepidophloios which could be 
recognized both by their internal structure and by their leaves, and also possessed 
two rows of tubercles. Similarly, in the first part of this paper, I have described 
specimens, both from the British Museum and from the Manchester Museum, which, 
to my mind, must be classed as .Lepidophloios and which possess only two rows of 
tubercles. 
There seems, therefore, to be no reason why the specimen under consideration should 
not be correctly described as a biseriate halonial branch of Lepidophloios fuliginosus. 
| Posrscript, November 20, 1902.— The specimen forming the subject of this Memoir, together with a 
number of sections cut from it, has been deposited in the Manchester Museum, Owens College.— 
E. E. W.] | 
-— ati a is 
