Geological Relations of the East of Ireland. 293 
and other vegetable remains. He remarked impressions very like 
the polypodium vulgare, a very large equisetum, and the stem, 
joints, and interior pith of plants resembling the euphorbias,^ 
§ 197. The top shale of the Lisnamrock coal seams is generally 
of a lighter colour than that of the roof, and less disposed to shiver 
and moulder on exposure to the atmosphere. But sometimes it is 
black, and of the character of drawing slate, or black chalk. 
The beds of clay ironstone in the top shale are commonly from 
one and a half to three inches thick, more or less continuous, and 
separated from each other by shale three and four feet thick. 
§ 198. Vegetable impressions are no doubt to be found in the 
sandstone of this district also, although I can record only a single 
observation. I found a loose stone in one of the fields, of the 
nature of quartzy sandstone, or rather of quartz itself, which pre- 
sents the same impression as is depicted by Martin, PI. 11. fig. L 
and PI. 12. fig. 2, and by Parkinson, vol. i. PI. 3. fig. 3; which are 
mentioned by both these authors as occurring likewise on sandstone.. 
The prototypes are conceived to belong to the cacti. 
§ 199. In descending the declining surface of this coal district 
toward the south-east, we find the hollows partly occupied by a 
deposit of limestone gravel, mixed with debris of sandstone and 
shale, which gradually increases in thickness as we approach the 
lower grounds. In this manner, even large boulders of limestone 
are found in the hollows at the distance of two miles from the lime- 
stone flat. 
§ 200. The outskirts of the Killenaule coal district consist of 
three hills, 'which stand in connexion between Cashel on the south- 
west and the limestone hollow or valley, which separates this small 
* Statistical Survey of the^County of Kilkenny. 
