BARK FLUTED AND SCARRED. 473 
The impressions, or scars, which formed the 
articulations of leaves on the longitudinal flutings 
of the trunks of Sigill arise, are disposed in ver- 
tical rows on the centre of each fluting from the 
top to the bottom of the trunk. Each of these 
scars marks the place from which a leaf has 
fallen of, and exhibits usually two apertures, by 
which bundles of vessels passed through the 
bark to connect the leaves with the axis of the 
tree. No leaf has yet been found attached to 
any of these trunks; we are therefore left entirely 
to conjecture as to what their nature may have 
been. This non-occurrence of a single leaf upon 
any one of the many thousand trunks that have 
come under observation, leads us to infer that 
every leaf was separated from its articulation, 
and that many of them perhaps, like the fleshy 
interior of the stems, had undergone decompo- 
sition, during the interval in which they w^ere 
floating between their place of growth, and that 
of their final submersion. 
M. Ad. Brongniart enumerates forty-two species 
of SigillarJa, and considers them to have been 
nearly allied to arborescent Ferns, with leaves 
very small in proportion to the size of the stems, 
and difterently disposed from those of any living 
Ferns. He would refer to these stems many of 
the numerous fern leaves of unknown species, 
which resemble those of existing arborescent 
genera of this family. Lindley and Hutton shew 
strong reasons for considering that Sigillariae 
