164« Mr. Griffith, on the Order of Succession of the Older 
from two inches to a quarter of an inch in diameter, imbedded 
in a reddish gray arenaceous base. The conglomerate is suc- 
ceeded by coarse-grained brownish-red slate, which is occa- 
sionally quarried and used for inferior roofing slate ; these strata 
are followed by a series of beds, consisting of red quartzose 
sandstone alternating with coarse slate, the sandstone beds 
presenting occasionally a conglomeritic character, but the 
pebbles rarely exceed half an inch in diameter. The strata 
dip to the west, though irregularly, at an average angle of 
about 10° from the horizon ; and consequently in ascending 
the glen in a southern direction, the cliffs present the out- 
going or strike of the beds, which are not horizontal, but ex- 
hibit a tortuous arrangement presenting frequent undulations 
from north to south. At Esknagluggerny, a short distance 
beyond the southern extremity of Coosane lake, the old red 
sandstone strata are cut off by the great north-west and 
south-east fault already mentioned, immediately to the south 
of which thick beds of green chloritic quartz rock appear at 
the surface, dipping to the south at an angle of 30° from the 
horizon. These strata probably form the lowest portion of 
the transition rocks situated to the south of Castlemaine Bay, 
as we perceive the whole series to be complete in an ascending 
order from them to the summit of the Reeks. 
Commencing then with this chloritic quartz rock base, and 
proceeding in a southern direction, we find that the same 
rocks continue to dip to the south, and present an accumu- 
lation of strata for upwards of 500 feet in thickness, varying 
little in their composition or character, with the exception of 
an occasional interstratification of thin beds of green and 
purplish gray clay slate. These slates are quite distinct in 
character, as well as in colour and composition, from the 
coarse red slate of the old red sandstone \ they are in fact 
identical with the Valentia slates, and bear a strong resem- 
blance in colour, composition, and lithological character to 
some of those of North Wales. Still ascending in the series, 
we find that the colour of the rocks gradually changes from 
green to gray, and at length the mineral chlorite is altogether - 
wanting. These gray quartzose beds are not so thick p 
those which contain chlorite ; they likewise alternate with thin 
beds of clay slate, which present a purplish gray colour, with- , 
out any admixture of green. The gray strata may amount 
altogether to about 800 feet in thickness. Still continuing to 
ascend, the same character and alternations are preserved as 
the last described, but on a fresh fracture the quartzose beds 
present a slight bloom or tint of red, and the disinlegramd 1 
surface of the rock exhibits a decidedly reddish hue, which ; 
