Henry H. Howorth — Geology of the Isie of Man. 411 
of a conglomerate, and occasional pockets and layers of Consolidated 
fine red mud. Tlie whole thickness is not more than twenty feet at 
any point. The conglomerate consists of a very closely packed 
series of boulders, some of tliem rounded and some with their 
edges sharp, imbedded in a matrix of Consolidated red mud, similar 
to tliat just mentioned. 
The boulders just referred to are of various sizes, from a foot and 
a foot and a half in diameter to small pebbles, and, so far as a careful 
and prolonged examination could discover, consist almost entirely of 
picces of limestone and quartz, the limestone forming about - L %- 
of the whole. These limestone boulders are some of them of the 
natural colour of the limestone, and others are deeply coloured with 
iron. These boulders are most clearly of Mountain Limestone, and of 
the same character as the bedded limestone close by, and but for the 
colour of a number of them, there would never have been any doubt 
that they were formed out of the disintegrated limestone. Again, 
the muddy matrix in which the boulders are imbedded, as well 
as the intercalated pockets, consists of a paste made up largely of 
pulverized limestone. 
These facts seem to adrnit of but one conclusion. A conglomerate 
consisting almost entirely of limestone boulders, imbedded in a 
matrix of pulverized limestone, lying immediately in contact with 
beds of limestone, cannot well by any process of reasoning be made 
into an “ Old Eed Conglomerate.” Unless there be some reason of a 
very marked kind to the contrary, the conclusion is inevitable that it 
has been formed of the disintegrated beds of Mountain Limestone, 
and is posterior in date to them. 
Thirdly, as to the position of these beds. Mr. Cumming says they 
underlie the limestone which rests conformably upon them. I have 
searched carefully the various points where they appear at Langness, 
on the banks of the river Santon, at Cushnahavin, and in Derby- 
haven bay, and nowhere can I find evidence to Support this State- 
ment. The sections exposed are nearly all on the coast, and are 
much obscured by the overgrowth of sea-weed, and by discoloura- 
tion, etc., etc. There was only one place where the sequence of the 
beds seemed to me unmistakable, and that was in the beds lying 
almost horizontally between high and low water mark in Derby- 
liaven bay, and there, certainly, as far as I could make out, the grey 
and dark coloured limestone was overlain by beds of an ochreous 
colour, still unmistakable limestone, and in every respect bedded 
likethe grey limestone just mentioned; above this red-coloured lime- 
stone again lay the beds of red conglomerate. Nowhere, as I have 
said, could I see any evidences that the conglomerate was overlain 
by the limestone, nor do I believe, after having tested the position 
carefully, that such a succession of the beds can be seen anywhere in 
this part of the island. On the contrary, north of the Santon 
brook, where, by the violence of the great discharge of trap, the 
beds are torn and twisted in an extraordinary fashion, a bed of 
limestone has been thrown up on end, and its lower surface has been 
bared, and we can examine very easily both its upper and lower 
