177 
1916-17.] The Hiirlet Sequence and the Abden Fauna. 
Sandstone Series. But in Sheet 31 and the accompanying Memoir that 
limestone is placed in the Calciferous Sandstone Series, and the thick lime- 
stone of Petershill is regarded as the equivalent of the Hurlet Limestone. 
In The Geology of Central and Western Fife and Kinross, published 
in 1900,* the Charlestown Limestone is taken as the equivalent of the 
Hurlet Limestone in the upper reaches of the Firth of Forth, and the 
Seafield Tower Limestone as its easterly extension in the neighbourhood 
of Kirkcaldy. This is the same view as that already expressed in the 
map published in 1867. 
In The Geology of Eastern Fife, published in 1902, f the White Coral 
Limestone seen on the shore near Coal Farm, St Monans, is taken as 
the equivalent of the Hurlet Limestone. We consider this to be the 
Blackbyre Limestone of the Hurlet district, the limestone lying im- 
mediately above this position exposed on the shore at Partan Crags, 
St Monans, being in the Hurlet Limestone position. 
Such is a brief summary of the conclusions arrived at by the officers 
of the Geological Survey in their original survey of the Lower Carboni- 
ferous Limestone Series of Midland Scotland. A detailed examination 
of these maps and memoirs will show that they were unable to advance 
any very definite stratigraphical or palaeontological evidence in support 
of the reasons which they had for adopting their Hurlet Limestone 
datum line in these widely separated localities. It will also be seen that 
after having fixed upon their Hurlet Limestone horizon everything above 
it in the Lower Limestone Series was grouped as the Hosie Limestones, 
and no attempt was made either to differentiate them out or to correlate 
them in detail. 
Within the last few years a revision of the Carboniferous Limestone 
Series has been undertaken by the Geological Survey, and in this revision 
most of the original determinations of the Hurlet datum line have been 
maintained, with the notable exception that the West Kirkton-Tartraven 
Limestone has again been taken as the equivalent of the Hurlet Lime- 
stone. 
The Geology of the Glasgoiv District was published in 191 1,J and in 
this Memoir we have the first official account of the Hurlet Section, as 
it has already been pointed out that the Explanatory Memoir to Sheet 30 
had never been published. This Memoir embodies the results of the 
* Memoirs of the Geological Survey of Scotland , District Memoirs : The Geology of Central 
and Western Fife and Kinross. 
t Ibid., The Geology of Eastern Fife. 
J Ibid., The Geology of the Glasgow District, 1911. 
VOL. XXXVII. 
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