254 
Mr. Weaver on the 
occasional slight layers of slate clay ; but I must add, on the autho- 
rity of Mr. Richard Griffith, junior, that this sandstone does occur in 
patches interstratified with the first floetz limestone at Daly’s Bridge 
on the south side of the clay slate in the county of Cavan, and again 
on the north-western side, toward the towns of Cavan and Belturbet. 
2. First Floetz Limestone . 
§ 154. This rock may be termed emphatically the floetz 
limestone of Ireland ; for, with the exception of the counties 
of Derry and Antrim in the north, and Wicklow in the east, 
there is no county in the island in which it does not more or less 
prevail. It exhibits considerable variety of character in different 
parts, in colour, structure, and hardness : and in travelling over its 
widely expanded field, we find it, both in unmixed continuous 
strata, and associated with rocks of various description, being inter T 
stratified with hornstone, lydian stone, flinty slate, slate clay, swine- 
stone, calp, clay slate conglomerate, limestone conglomerate, mag- 
nesian limestone, brown spar, trap, and porphyry. 
§ 155. This great sheet of limestone comes in contact with, 
and sweeps round every mountain tract which we have hitherto 
noticed, filling up every interval and hollow between them. In 
its line of apposition to older rocks, it generally follows for a cer- 
tain distance the inclination of surface which they present ; but in 
the interior of the field we may observe a greater uniformity of 
arrangement. In the northern and greater portion, whether we 
examine it by crossing the country to the south from the clay 
slate hills of Longford, Cavan, Meath, and Louth ; or follow in the 
same manner the rocky coast on the east, we find the general 
range to approach toward the east and west, and the dip toward th^ 
south. In the central portion of the tract, the arrangement is 
