128 PllOCEEDINGS OF THE GEOLOGICAL SOCIETY. [DeC. 20, 



which vast numbers of drifted trunks of this species occur in some 

 places. The fourth species, D. annulatum, presents a very pecuhar 

 structure, probably of generic value. It has alternate concentric rings 

 of diseigerous woody tissue, of the character of that of Dadoocylon, and 

 of compact structureless coal, which either represents layers of very 

 dense wood or, more likely, of corky cellular tissue. In the latter 

 case the structure would have affinities with that of certain Gnetacece 

 and of Cycads. 



Though coniferous trees usually occur as decorticated and pros- 

 trate trunks, I have recorded the occurrence of one erect specimen, 

 in a sandstone a little above the " Main Coal," at the Joggins'. It 

 probably belonged to the species last named. Tissues of coniferous 

 trees are very rare in the coal itself. Most of the diseigerous tissues 

 found in the coal belong to SigiUaria and Calamodendron. From the 

 abundance of coniferous trees in sandstones above and below the coal, 

 and their comparative absence in the coal and coal-shales, it may be 

 inferred that these trees belonged rather to the uplands than to the 

 coal-swamps ; and the great durability and small specific gravity of 

 coniferous wood would allow it to be drifted, either by rivers or ocean- 

 currents, to very great distances. I am not aware that the fruits of 

 pine trees occur at the Joggins, unless some of the Trigonocarpa are 

 of this character. Nor has any foliage of these trees been found ; 

 but at Tatmagonche, in the continuation of the Upper Coal-formation, 

 there are leafy branchlets which I have named Araucarites gracilis, 

 and which may possibly have belonged to Badoxylon materiarium. 



The casts of pith-cjdinders known as Bternhergice are abundant 

 in some of the sandstones, especially in the Upper Coal-formation. 

 I have shown that in Nova Scotia, as in England, some of thes§ sin- 

 gular casts belong to Dadoccylon* ; but as the pith-cylinder of ^igil- 

 laria and of Lepidojphloios was of a similar character, those which are 

 destitute of woody investment cannot be determined with certainty, 

 though in general the transverse markings are more distant in the 

 Sternbergioi of Sigillaria and Lepidojphloios than in those of Dado- 

 ooylon. 



In Plate Y., and in Plate VI. fig. 14, I have given illustrations of 

 the coniferous plants above referred to. 



3. Sigillarice. — I have catalogued or described no less than twenty- 

 one species belonging to this family, from the Coal-measures of Nova 

 Scotia. They may be arranged under the following provisional 

 genera : — 



(1.) Favxjlaeia, Sternberg . .. . Sigillaria elegans, Brongyi. 



tessellata, Brongn. 



Bretonensis, Dawson. 



(2.) Rhttidolepis, Sternberg . . scutellata, Brongn. 



Schlotheimiana, Brongn. 



Saullii, Brongn. 



Dournaisii, Brongn. 



Knorrii, Brongn. 



^ Proceedings of the American Association, 1837, Canadian Naturahst, vol. ii. 

 Paper on Structures of Coal, Quart. Journ. Geol. Soc. 1860. 



