J 853.] DAWSON — COAL-MEASURES, NOVA SCOTIA, 3/ 



are occasionally found among drifted plants at the Joggins. As at 

 Pictou and elsewhere, they appear to be of different species ; some 

 belonging to rush-like plants and having only a thin coaly invest- 

 ment, and others surrounded with a considerable thickness of car- 

 bonized or petrified wood. I shall here refer merely to a few exam- 

 ples of the latter kind, which is comparatively rare in the Nova 

 Scotia coal-measvires. Figs. 26 & 27, ms. represent cross sections of two 

 specimens found in the irregularly-bedded sandstones of Group XIX. 

 In both the internal sandstone cast is finely striated transversely, 

 with less distinct longitudinal striae, and both are enveloped by clear 

 coal without structure. The coaly envelope of fig. 26, ms. is 1 inch 

 in diameter, and is striated, or finely ribbed longitudinally. That of 

 fig. 27, MS. is much flattened and somewhat smooth : its greatest dia- 

 meter is 1 foot. Another specimen (17 «, ^) has strong transverse 

 wrinkles, nearly a line apart, but in places meeting and uniting : 

 they occur at the edges of transverse internal coaly partitions. The 

 coaly matter investing this specimen, which is about half an inch in 

 thickness, shows the structure represented in fig. \7 b, ms. which 

 resembles that of an erect tree {SigiUaria ?) represented in fig. 21c. 

 This last species is very distinct in its external markings from the 

 ordinary Artisia approxhnata ; which, however, the specimens re- 

 presented in figs. 26 & 27, ms. much resemble. 



6. Structure of Erect Trees. — Beside the two erect trees (14 a, ms. 

 and fig. 5, p. 26) whose structure, probably coniferous, is represented 

 in figs. 6 & 7, p. 27, and fig. 18, I sliced specimens from nearly all the 

 other coaly erect trees found in the section, and found structure in 

 two of them (figs. 19 & 20). That in fig. 19 is probably coniferous, 

 though the structure is too imperfectly preserved to allow any cor- 

 roborative evidence to be obtained from longitudinal slices. Fig. 20 

 is from a coaly mass representing the base of a stump just at the 

 surface of an underclay, and having the structure preserved only in 

 one small portion, which may have been an internal core or ligneous 

 axis. It consists of a very large and open structure of elongated cells, 

 in irregular groups, separated by partitions of opake coal. Though 

 the longitudinal structure is very well preserved, I could detect no 

 traces of any markings on the walls of the cells. 



Fig. 21, «, 6, c, shows the structure of fragments of wood found in 

 the tree containing reptilian remains. In the longitudinal section this 

 wood shows, when highly magnified, cells or ducts with a sort of 

 scalariform structure, fig. 21 a, like that of Ferns. The cross section 

 shows an unequal cellular tissue, usually much compressed and im- 

 perfectly preserved, fig. 21c. In large slices the tissue is seen to 

 run in radiating lines, and there is an appearance resembling lines of 

 growth, fig. 216. 



7. Animal Remains. — The remains of Fish found in the section 

 consist of detached scales, teeth, jaws, spines, and coprolites. Most 

 of them are small, and belong to the families of which Palceoniscus 

 and Holoptychius are types. There are also a few rounded scales of 

 Sauroid fish, approaching in form to those of Mcgalichthys. These 

 fishes nnist have abounded in the creeks, lagoons, and channels of 



