34 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [NoV. 2, 



named genera had Stigmaria-roots. I may remark, however, that 

 some of the miderclays contain irregular coaly root-like bodies, which, 

 if not the roots of coniferous trees, may possibly belong to some of 

 the genera above mentioned. 



2. Coniferous Trees. — Trunks of this description occur in the 

 sandstones, both in a carbonized state and petrified by carbonate of 

 lime. It is observable that they are most abundant in those parts of 

 the section where the swamp-conditions of the productive coal- 

 measures begin to disappear, and where drifted plants predominate 

 over those which have grown in situ ; in other words, in the sand- 

 stones above and below our Section. Two specimens of these drift- 

 trunks were found, on being sliced, to have the characters of the 

 genus Pinites, with medullary rays having two rows of cells, and 

 cellular tissue with two, or more frequently three, series of hex- 

 agonal areolae. One of them much resembles P. Brandlingii of 

 Witham, The prevalence of coniferous trees as drift-wood in the 

 sandstones, above and below the Coal-measures, is probably to be 

 attributed to their capability of floating for a long time without be- 

 coming water-soaked and sinking, though it may also indicate that 

 their principal habitat was farther inland than the Sigillaria-swamps. 

 The erect coaly trees, however, already noticed, show that they did 

 grow in those swamps, though not abundantly. The structure of 

 the coaly coniferous tree above the main coal and its present position 

 in the beds are shown in figs. 5, 6, 7, pp. 26, 27. 



3. Calamites. — These plants appear erect and in situ at eight or 

 nine distinct levels, and in some of the beds their roots and ver- 

 ticillate leaves or branchlets may be seen attached to the stems. At 

 least two species occur ; one of them resembling C. Suckoivii or 

 C. canncBformis, the other a coarse and irregularly marked species. 

 Figs. 19 & 24, MS., and figs. 12, 13, 16 refer to the former species, fig. 

 15 to the latter. The Calamite-stems, when they can be traced to their 

 bases, always terminate in obtuse points, the joints becoming shorter 

 toward their extremities. The roots when not compressed are cylin- 

 drical, irregularly branched (figs. 13, 14), and covered with a thin coaly 

 bark, marked veith waving longitudinal striae. The roots are given 

 off not only from the base of the stem, but also from its lower joints, 

 in large irregular tufts; see fig. 14, where three of these tufts are 

 seen, and also irregular marks showing the places from which others 

 have been broken off. The coaly investment of the stem is much 

 thickened at the points from which the tufts of roots proceed. It 

 was the habit of the Calamite to grow on mud and sand flats risins: 

 by new depositions, and it appears that the joints which were buried 

 during the growth of the plant gave off" tufts of roots instead of 

 branchlets. The lower or underground joints of the Calamite had 

 also the power of sending out new stems, which speedily attained to a 

 greater diameter than that of their parent. In this way groups of 

 stems were produced, and the plant was enabled constantly to 

 maintain its position at the surface of the rising mud flats. Fig. 12 

 represents a fine specimen which well illustrates this peculiarity. 

 The stem a stands at right angles to the bedding of a thinly 



