KIDSTOX : THE FLORA OF THE CARBONIFEROUS PERIOD. 
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were named Halonia (Plate LTIL, fig. 2) before their true nature was 
known. In this condition the stem bears spirally-placed rows of 
mamillae-like protuberances, but in the corticated condition the 
depressions between the mamillae were filled up with the cortex, so 
that when the bark is present they rise little above the general level 
of the branch (Plate LV., fig. 2). 
The structure of the stem is similar in type to that of Lepidoden- 
dron, though the secondary wood appears to be produced at a later 
period and in some species it has not yet been observed. 
Lepidophloios occurs in both the Upper and Lower Carboniferous. 
Lepidostrobus Brongniart. In Lepidostrobus are placed the 
cylindrical, ovoid, or oblong cones with a ligneous axis and single- 
nerved bracts or sporophylls 
arranged in spirals (Plate LIL, 
fig. 2, and Plate LY., fig. 3). 
The bracts consist of two parts, 
a basal portion or pedicel spring- 
ing from the axis almost at right 
angles, and on which is placed 
the sporangium, and a limb 
which extends upwards at an 
acute angle from the extremity 
of the pedicel, Text Fig. 4. The 
lower bracts bear the macrosporangia, and the upper the micro- 
sporangia. The macrospores are smooth or apiculate and are provided 
with a triradiate ridge. 
Lepidostrobi are extremely common in Carboniferous strata, but 
in the majority of cases it is impossible to refer them to the parent 
plant, hence they are placed in the provisional genus Lepidostrobus, 
in which are included cones belonging to Lepidodendron, Lepidoph- 
loios, and Bothrodendron. 
Lepidophyllum Brongniart. Lepidophyllum embraces the single- 
nerved, more or less lanceolate leaves so frequently met with, 
and which it is impossible to refer to the plants which have borne 
them. Text Fig. 5. They belong in part to Lepidodendron and 
Lepidophloios, and also to some Sigillaria. 
b 
Fig. 4. — Lepidostrohm — c, axis; h, 
hiact or sporophyll, bearing sporan- 
gium d, containing macrospores ; 
a, limb of bract. (Restored.) 
