476 STIGMARIA. 
formation, nearly one half, out of eighty known 
species of Arborescent plants, have their leaves 
growing in parallel series. The remaining half 
are Lepidodendra, or extinct Conifera^. (See 
Lindley and Hutton, Foss. Flora, vol. ii. p. 93.) 
Stigmaria.* 
The recent discoveries of Lindley and Hutton 
have thrown much light upon this very extra- 
ordinary family of extinct fossil plants. Our 
figure, PI. ^6, Fig. 8, copied from their engraving 
of Stigmaria ficoides, (Foss. Flora, PI. 31, Fig. 1) 
represents one of the best known examples of the 
genus.t 
The centre of the plant presents a dome-shaped 
trunk or stem, three or four feet in diameter, the 
substance of which was probably yielding and 
fleshy ; both its surfaces were slightly corru- 
gated, and covered with indistinct circular spots. 
(PL 56, Fig. 8. ,9.) 
From the margin of this dome there j)roceed 
many horizontal branches, varying in number in 
different individuals from nine to fifteen ; some 
of these branches become forked at unequal dis- 
tances from the dome ; they are all broken off 
* PI. 56, Figs. 8.9. 10. 11. 
t Seventeen specimens of this kind have been found within 
the space of 600 square yards, in the shale covering the Benshani 
seam of coal at Jarrow Colliery near Newcastle, at the depth of 
1200 feet. 
