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conical termination, like Catamites ; secondly, in the quin- 
cuncial scars being united by elevated lines, producing a 
lozenge- shaped pattern, unlike any plant with which I am 
acquainted; thirdly, in the scars being elevated above the 
surface, while in Stigmaria they are depressed below it. 
Hence the question arises, has this specimen been the ter- 
minal portion of one of the tertian* radicles of the Stig- 
maria ? If so, it is another important acquisition to our 
knowledge of the structure of that plant. Or has it been 
the terminal portion of the stem of a solitary plant having 
a growth like Catamites, and like it possessing the same 
ambiguity of character, as to whether it was an Aphyllous 
succulent plant like Stapelia, or bearing narrow acicular leaves 
like the larch, from each circular scar, which is highly probable ? 
(See plate I.) In Catamites a uniformity of external structure 
pervades the whole plant. The termination of the stem, 
like that of equisetum, is conical ; and the root, which is 
lateral in position, resembling a Rhyzoma, terminates some- 
what abruptly, exhibiting, however, the transverse, or annular 
lines, so characteristic of the genus, but in closer approxima- 
tion, and each gradually less in circumference towards the 
centre or extremity. 
As considerable diversity occurs in the sizes, form, number, 
and distance of the scars on different specimens of the so- 
called Stigmaria, is it not probable that two distinct plants, 
or rather roots, may have been confounded under the general 
name of Stigmaria ? That some noble specimens in the 
museum of the Leeds Philosophical and Literary Society, 
which exhibit the first branching of a large bifurcate 
root, have been such there cannot be doubt. But that 
they were the caudex, giving origin to the smaller and 
numerous fragments of the common Stigmaria, appears very 
doubtful ; since, in the quarries from Headingley Moor, from 
whence they were obtained, I have never seen or heard of a 
