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Proceedings of the Royal Society of Edinburgh. [Sess. 
elements and to refer them to a separate wedge of xylem, a point so easy 
to determine in the other described Sagillarice. The protoxylem elements 
are small and few in number (fig. 2, a), but the tracheids of the centrapetal 
xylem are large and irregularly placed, with little or no tendency to become 
arranged in lines (fig. 2, b). 
The tracheids of the secondary xylem are smaller, though they 
gradually increase in size from within outwards, and are arranged in 
definite rows with their associated medullary rays (fig 2, c ). 
The occasional absence of a prominent crenulate margin to the primary 
xylem connects this type of stele structure with those of the Lepido- 
dendrece which do not possess a corona. 
Scattered throughout the matrix are several transverse sections of 
leaves which sometimes show the double vascular trace of Sigillariopsis. 
In both the specimens described here, some leaves with a single, and some 
with a double, vascular strand occur, and it is almost impossible to doubt 
that these leaves belong to the Sigillarian stems which accompany them. 
On the presence of a double vascular strand in the leaves, Renault founded 
his genus Sigillariopsis, but it is evident that this genus can no longer be 
regarded as distinct from Sigillaria, seeing that Sigillaria scutellata, with 
which they occur — and, I doubt not in this case, is the plant to which they 
belong — is the type of the genus Sigillaria, Brongniart. 
The other characters of the genus Sigillariopsis are similar to those of 
the Glathrate Sigillarice, to which group Renault’s type specimen belongs. 
When, therefore, it is seen that both the Glathrate and ribbed Sigillarice 
possess leaves with the structure of Sigillariopsis, the latter genus loses 
all individuality. It must be remembered that the leaf strand is not 
double throughout the whole of its course, and that only certain sections will 
show this character. 
My thanks are due to Mr G. IT. Knott for his kindness in placing these 
interesting specimens in my hands for description. 
( Issued separately August 28, 1907.) 
