discovered in Craigleith Quarry. 151 



phanerogamic plant. %dly, Having examined with care the in- 

 ternal structure of this fossil tree under the microscope, agreeably 

 to the rules laid down in my Observations upon Fossil Vegetation, 

 I find it cannot belong to the former of these classes It has, how- 

 ever, most decided medullary rays, and a woody texture, with 

 some appearance of concentric circles, and must therefore belong 

 to the order Coniferae. (See Plate IV. Figs. 1 and 2.) It cannot 

 be a Cycas or a Zamia, and a Lycopodium it cannot possibly be, 

 these plants being vascular cryptogamic, composed of cellular tis- 

 sue withscular fibres, destitute of medullary rays, concentric rings, 

 or woody texture, and generally dichotomous. Great numbers of 

 these gymnospermous phanerogamic plants have lately been dis- 

 covered in the shales of the mountain-limestone groups, much 

 broken, and lying in a state of great confusion. This gigantic 

 stem so far exceeds in size the generality of those found in similar 

 situations, that although possessing, in common with the rest, the 

 same general character, yet I fear, with our present limited know- 

 ledge in this hitherto neglected field of botany, it would be dan- 

 gerous, or rather impossible, to name the genus. I may here men- 

 tion, that the concentric rings so very apparent in plants belong- 

 ing to the oolitic series, are not in general so conspicuous in 

 those found in the mountain-limestone series and coal-fields ; pro- 

 bably, amongst other causes, owing to the abundance of calca- 

 reous matter, and the peculiarity of crystallization ; yet, from the 

 examination of the few slices of this tree already cut, I feel per- 

 suaded that they will be found in many parts of its magnificent 

 trunk. 



Since commencing this short account, a fragment of a third fos- 

 sil stem, with a branch, has been discovered on the south side of 

 the same quarry, between where the fossil discovered in the year 

 1826, and that found in 1830, lay. This fragment and branch 

 were imbedded in one of those indurated parts of the rock called by 



u 2 



