The Coal of Australia. 
443 
downwards as in Casuarina, about half the diameter of the stem ; 
they do not arise from every joint, but they do nearly; I am 
uncertain whether more than one spring from any one joint. 
Most of the stems are perfectly smooth, being striated only at 
the articulation, while others have a delicate lineation down 
the internodes; the first I imagine to be stript of their bark, 
and the latter to retain it; and here again we have another 
proof of the stronger affinity of our fossil to Casuarina than 
to Equisetum, for I find by examining the living Casuarina: 
that the lineation of the surface goes no deeper than the bark, 
while the elevated lines on the surface of Equisetum are only the 
edges of strong septa going towards the central hollow, and the 
flat spaces between those lines are only the superficial coverings 
of tubular hollow spaces between the aforesaid septa, so that de¬ 
stroy the surface of Casuarina and you render the stem smooth— 
destroy the surface of Equisetum and you only increase the 
coarseness and strength of the sulcation. I may also add (in 
accordance with this view) that age or size has no connexion with 
this lineation of the surface, as is suggested by M. Brongniart 
in the last few lines of the quotation from his work at the head 
of this subject, for I find some of the largest stems perfectly 
smooth and the smallest occasionally striated. The sheaths are 
rather coarsely striated, and terminate in thin, flattened leaves, 
the midrib of which is scarcely discernible. In the weeping or 
downward curved branches the leaves are completely reflexed so 
as to point upwards, and according to the position of the stem, 
are either reflexed, expanded, or lying straight up against the 
stem. The stems vary from 3 to 7 lines in diameter. 
Common in the white soft shale of Mulubimba, N. S. Wales. 
Phyllotlieca Iiookeri (M’Coy). 
Sp. Char. Stem simple, coarsely sulcated and ridged longitudi¬ 
nally ; sheaths very large, loose, subinfundibuliform, each 
sheath extending from one articulation to the next, so as to 
conceal the stem ; leaves about twice the length of the sheaths, 
thick, narrow, and with a strong, prominent midrib. 
This species is easily known from the two former by its great 
