On Sigillaria Brardiu and its Variations. 237 
Here the Leiodermarian condition is not brought about by an 
increase in girth in the stem, but is evidently produced by 
a rapid upward growth of the plant which distanced the 
leaf-scars, and prevented the formation of the “cushions.” 
A similar condition of circumstances is seen occasionally in 
the Rhytidolepis section, and examples of such have been 
figured by Lesquereux! and Zeiller.2. The approximation of 
the leaf-scars also usually occurs in the Rhytidolepis group in 
the region of the cone-scars, caused evidently by the drain 
on the resources of the plant in supporting the fructification. 
In the various forms of Sigillaria Brardii, the form of the 
leaf-scar varies very little. 
The description of Sigilarva mutans, as given by Weiss 
and Sterzel, is partly adopted here in my description of 
Sigillaria Brardw, with which it is synonymous. 
SIGILLARIA Brarpil, Brongniart. 
[Plate VII., Figs. 1 and 2.] 
1822, Clathraria Brardii, Brongt., Class. d. végeét. fess., p. 22, pl. i., fig. 5 
(in Mém. du Mus. d’hist. nat., vol. viii.). 
1828. Sigillaria Brardii, Brongt., Prodrome, p. 65. 
1836. i »  Brongt., Hist. d. végét. foss., p. 430, pl. elviil, 
fig. 4. 
1845, e ‘s Geimar, Vers. d. Steink. v. Wettin u. Lébejun., 
Heft. iii., p. 29, pl. xi., figs, 1 and 2. j 
1857. ” i; Goldenberg, Flora Sarep. foss., Heft. ii., p. 25, 
pl. vii., figs. 7, 8 (? fig. 10). 
1870. . + Schimper, Traité d. paléont. veget., vol. ii., p. 102, 
pl. Ixvii., figs. 10, 11. 
1871. 53 » Weiss, Fossile Flora d. jiingst. Stk. u. Rothl., 
Heft ii., p. 161, pls. xvi., fig. 1; xvii., figs. 7-9 
(includes vars. subquadrata and transversd). 
1880. bas a Zeiller, Végét. foss. terr. houil. de la France, 
p. 135, pl. elxxiv., fig. 1. 
1881. re n Renault, Cours d. botan. fuss., vol. i, p. 129, 
pl. xvii., fig. 1. 
1 Sigillaria mammilaris, Lx., Coal Flora, vol. iii., pl. eviii., 1884. 
2 Sigillaria suwvewri, Zeiller, Flore foss. Bassin houil. d. Valen., pl. Ixxxiv., 
fig. 1, 1886. I possess a specimen of this plant from Staffordshire, showing 
‘a similar condition, 
VOL, XIII. R 
