On Sigillaria Brardii and its Variations. 241 
1893. Sigillaria ambigua, Weiss and Sterzel, ibid., p. 172, pl. xx., fig. 79. 
1888. Sigillaria, Weiss, Zeitsch. d. deut. geol. Gesell., p. 568, figs. 1, 2. 
1836. Lepidodendron Oltonis, Gopp., Syst. fil. foss., p. 462, pl. xlii. 
figs. 2, 3. 
1860. Lepidodendron sexangulare, Lichw. (not Gipp.), Letheea Rossica, vol. 
Is) De LL 4s pliaves fe. 8 (2 fig, 9); 
1838. (2) Aspidiaria Schlotheimiana, Pres]. in Sternb., Vers., li., p. 181, pl. 
Iviii., fig. 10 (excl. refs.). 
Description.—Leaf-scar rhomboidal, as long as broad, but 
often broader than long; upper margin rounded, flattened, 
or notched, lower margin rounded, sides generally convex 
with sharp lateral angles. Cicatricules three, placed slightly 
above the centre of the leaf-scar, the central cicatricule 
transversely linear, generally concave, the two lateral 
oblique, frequently lunate, embracing the central cicatricule ; 
above the leaf-scar there is frequently a small circular 
cicatricule. 
Leaf-cushion. <A definite limit of the cushion often absent 
(Leiodermaria), occasionally incomplete (swb-Leiodermaria or 
sub-Cancellata), or distinct (Clathraria or Cancellata). Leat- 
cushion, when present, more or less elevated, generally 
rounded above and below, or subquadrate or spathulate with 
truncated base, and generally without any surface orna- 
mentation. Leaf-scar usually on the upper portion of the 
cushion, central only in the young condition. 
Cortex. On the Leiodermarian or sub-Leiodermarian forms, 
the outer surface of the bark, between the leaf-scars, is 
generally ornamented with a shagreen-like sculpturing of 
fine longitudinal ridges and delicate transverse striz. The 
longitudinal lines are longer and coarser than the fine 
transverse strize; under the leaf-scar the bark is frequently 
smooth,—above the leaf-scar it is generally smooth. 
Immediately beneath the leaf-scar on certain Leioder- 
marian forms there sometimes occur one or two small 
circular scars. 
Cortex thin—decorticated stem longitudinally striated. 
The cone-scars form an irregular girdle round the stem. 
They are small, circular, oval, or subtriangular, and in the 
Clathrarian forms are placed on small cushions inserted 
between the leaf-scars, which, like the cone-scars, are usually 
