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OLD RED SANDSTONE OF WESTERN EUROPE. 431 
2. Dull red pebbly sandstone, 
1. Brecciated conglomerate, 
(Fault). 
Clay slates. 
Owing to the large fault at Gardenstoun, and to one or two of minor extent 
on the shore, it is not possible to estimate satisfactorily the thickness of these 
various beds until the ground has been surveyed in detail. Their total depth 
probably does not fall much short of 1000 feet. Nos. 1 to 4 may be parallelled 
with the basement beds on the shore in Aberdour Bay. There can be little doubt 
that the coarse brecciated conglomerate (5 and 7) containing the ichthyolite- 
bearing clays (No. 6) is the same as that which forms so conspicuous a feature 
of the coast between Gamrie and Aberdour. I did not observe the ichthyolite 
beds along that coast, but Dr Matco_mson mentions the occurrence of shales 
with nodules like those of Gamrie, a little below the Manse (Mains) on the 
estate of Auchmedden. 
The argillaceous zone containing the ichthyolites is exposed in two ravines on 
either side of the farm of Findon. It occurs likewise at several points further 
inland where water-courses have cut down through the overlying conglomerate, 
as on the road below Cushnie. In one of the upper bands of bluish-grey 
shaly clay, about three or four feet thick, nodules of grey impure fetid limestone 
occur. These nodules are flattened disks, averaging perhaps six or eight inches 
in diameter. The limestone of which they consist is distinctly stratified, as may: 
be best seen upon weathered surfaces, and it breaks open along the lines of 
deposit, but more particularly along the middle, which is usually occupied by a 
flattened ichthyolite. Most of the nodules are crusted over with an outer 
layer of fibrous limestone, about an inch in thickness, the fibres being directed 
inwards towards the centre of the stone. This peculiar feature is one of the 
characteristics of the fish-bearing nodules along the whole of the southern 
borders of the Moray Firth. It reappears likewise at Cromarty. Though 
usually in detached pieces the fish are admirably preserved in these nodules. 
Their colour is a dull yellowish or brownish horn-like grey ; none of them have 
the deep black of the Cromarty beds, nor the rich colours of those of Altyre 
and Tynet Burn. 
The true horizon of these Gamrie beds is well brought out by a list of their 
ichthyolites. The following species were named by Agassiz as coming from this 
locality :—Cheiracanthus Murchisoni, Diplacanthus longispinus, Cheirolepis oura- 
gus, Diplopterus affinis, Glyptolepis elegans (common), cruihid major, O. 
arenatus, Pterichthys Milleri, P. oblongus. 
Though the Gamrie outlier extends so far inland, few good sections are to be 
seen after we leave the coast, and the ravines leading down to it. About two 
