Mr.Gourlie <m the Fossil Plants in the Glasgow Geological Museum. 107 



Calamites. — Tho fossil plants referable to the genus Catamites of 

 Brongniart, and other authors, occur profusely in our coal fields, as well 

 as in those of the north of England. They are found in a state of 

 compression, which renders it difficult to determine their species, or to 

 form an idea of their probable affinity to plants of the present day. 

 Judging from the remarkable compression of even the largest speci- 

 mens, it is likely that the calamite had a hollow jointed stem, with 

 transvere phragmata, resembling that of the bamboo cane, and, at 

 least in some species, with verticillate branches, which again have ver- 

 ticillate leaves. Brongniart thinks that the calamites must have had a 

 close affinity to the recent genus Equisetuniy from their striated, or 

 rather furrowed, jointed stems, and the presence in one of his speci- 

 mens of what he takes to be a sheath ; but the objection to this view 

 is, that they appear to have had both wood and bark, and consequently 

 with the habit of a monocotyledonous plant, they come nearer the dico- 

 tyledones in structure. A specimen from the Duke of Hamilton in 

 this collection was found in the sandstone in an upright position, and 

 shows the form of the stem without the usual compression ; but it is 

 apprehended, that even were it possible to form a thin polished section, 

 it would exhibit no trace of structure. 



Sigillaria. — A number of specimens in the museum belong to the 

 genus Sigillaria, so named from sigillum, a seal, on account of the 

 peculiar impressions on the stems. Less is known of this genus than 

 even the calamites, and similar forms are quite unknown in the vege- 

 tation of the present day. They are found inclined in all directions, 

 sometimes passing vertically through beds of sandstone, but most fre- 

 quently in a horizontal position, and then they are crushed so extremely 

 thin, that they seem to have been hollow like the calamite, and to have 

 possessed very little substance, although attaining a height of forty or 

 fifty feet. The compressed stems have been found as much as five feet 

 in breadth, and some fragments now produced, particularly a portion 

 of 8. renifonnis, must have belonged to a very large individual. They 

 are generally fluted longitudinally, and marked at regular intervals 

 with single or double scars, evidently produced by leaves which have 

 been articulated to the stem. These marks are different in the decor- 

 ticated state of the fossil from those which appear on the surface of 

 the coaly envelope representing the bark ; this is well seen in the SigiU 

 laria reniformis. M. Brongniart considers these to be remains of tho 

 stems of arborescent ferns ; but we incline to the view of Messrs. Lindley 

 and Ilutton, who have established that the fluted Sigillarice have 

 nothing analogous to tree ferns. On the contrary, they appear to have 

 been plants with hollow cylindrical stems, consisting of wood and bark, 

 and clothed with leaves— attaining a height of forty to sixty feet— but 

 belonging to a family with no representative, or even relation, in the 

 flora of our day. 



Lepidodendron. — This genus of fossil plants is one of great interest, 

 not only on account of its abundance, and the elegance and beauty of 



