KIDSTOX: THE FLORA OF THE CARBONIFEROUS PERIOD. 201 
of stem. The aerial stems of Calamites spring from creeping 
rhizomes as seen in the figure of Calamites Suckowii, given on 
Plate XXX., fig. 1, as well as from the subterranean portion 
of the aerial stems (Plate XXXV., fig. 3). 
Let us now return to the consideration of the three groups 
of stems, to which reference has just been made : — 
I. — Calamitina. 
Calamites varians Sternb. may be taken as typical of tliis 
group (Plate XXXIV., fig. 1. Calamitina varians var. inconstans 
Weiss). 
The internodes vary in length, and the nodes bear closely- 
placed transversely oval leaf scars. The bark is smooth but 
frequently shows slight longitudinal clefts or cracks, which vary 
in their length and distance apart. These longitudinal cracks 
or lines probably arise through the splitting of the bark from 
the increase of the stem in girth. Between each branch-bearing 
node several branchless nodes intervene, their number varying, 
not only in the same species, but even on the same specimen. 
The foliage of some Calamitince consisted of acicular leaves, but 
whether all possessed such foliage is not known (Plate XXXVL, 
fig. 1). 
II. EUCALAMITES. 
Calamites ramosus Artis. is representative of this section 
(Plate XXXVII., figs. 3 and 4). Each node gives rise to two 
branches, one on each side of the stem. The branches are super- 
posed, and, though these again bear lateral branches, the plant 
would possess the form of a triangle. The surface of the 
stem is smooth. Plate XXXVII., fig. 4, shows the cast of the 
pith cavity ; fig. 3 shows the outer surface of the species with 
smooth bark. 
The foliage of Calamites ramosus consisted of lanceolate leaves, 
arranged in whorls and united by their bases to form a very narrow 
ring round the stem. This foliage was named Annularia radiata 
by Brongniart before it was discovered to be the foliage of 
Calamites ramosus (Plate XXXVII., fig. 1). 
