or extinct Coniferæ. (See Lindley and Hutton, Foss. Flora, vol. ii. p. 93.)
Stigmaria.[1]
The recent discoveries of Lindley and Hutton have thrown much light upon this very extraordinary family of extinct fossil plants. Our figure, Pl. 56, Fig. 8, copied from their engraving of Stigmaria ficoides, (Foss. Flora, Pl. 31, Fig. 1) represents one of the best known examples of the genus.[2]
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 corrugated, and covered with indistinct circular spots. (Pl. 56, Figs. 8. 9.) .
From the margin of this dome there proceed many horizontal branches, varying in number in different individuals from nine to fifteen; some of these branches become forked at unequal distances from the dome; they are all broken off short, the longest yet found attached to the stem, was four feet and a half in length. The extent of these branches, when outstretched and perfect, was probably from twenty to thirty feet.[3] The surface of each branch is covered with
- ↑ Pl. 56, Fig. 8. 9. 10. 11.
- ↑ Seventeen specimens of this kind have been found within the space of 600 square yards, in the shale covering the Bensham seam of coal at Jarrow Colliery near Newcastle, at the depth of 1200 feet.
- ↑ It appears from sections of a branch of Stigmaria, engraved by Lindley and Hutton, (Foss. Flora, Pl. l66,) that its interior was a hollow cylinder composed exclusively of spiral vessels, and containing a thick pith, and that the transverse section exhibits a structure something like that of Coniferæ, but without concentric circles, and with open spaces instead of the muriform tissue of medullary rays. No such structure is known among living plants.
These cylindrical branches are usually depressed on one side, probably the inferior side (Pl. 56, Figs. 8. ab. and 10. b.;) adjacent to this depres-
