198 Proceedings of the Royal Society of Edinburgh. [Sess. 
The section in the Bilston Burn is situated about 7 miles to the south 
of Edinburgh, and begins just where the stream crosses the road at the 
Bilston Inn. The details of this section need not be repeated here. The 
following table shows our correlation of the main calcareous horizons with 
those of the West of Scotland : — 
Bilston Burn. 
. Bilston Burn Limestone. 
Vexim Limestones. 
North Greens Limestone. 
Gilmerton Limestone. 
Limestone with Hurlet Alum 
Shale fauna in shale below. 
X. Section at Aberlady Bay. 
The Lower Carboniferous Limestone Group at Aberlady Bay is exposed 
between high and low water marks in a continuous section north of 
Aberlady and west of Kilspindie as far as Craigielaw Point. The beds 
are gently undulating, forming a syncline in the east and an anticline in 
the west. The dominant dip of the strata is southerly and parallel to the 
pitch of the folds. The section exposed is as follows : — 
Ft. In. 
14. Dark Shale with thin Limestone of Craigielaw Point . . .... 
F. 13. Hard grey Limestone with encrinites and Productus giganteus . 12 
12. Thin Coal and Fireclay . . . . . . . .... 
11. Shale 7 
E. 10. Hard grey Limestone with Productus giganteus .... 2 
9. Thin Coal in places ......... 3 
8. Shale ........... 8 
7. False Bedded Sandstones ........ 4 
6. Sandy black Shale ..... ... 8 
D. 5. Nodular dolomitic encrinital Limestone . . . . .12 
4. Coal ............ 10 
3. Grey Shale and Fireclay full of twisted rootlets .... 6 
B. 2. White Coral Limestone ........ 8 
1. Grey and greenish Shales, and yellow Sandstones . . .20 
The White Coral Limestone, No. 2 in the above table, is identical with 
that seen at Coal Farm, St Monans, as has been pointed out by Dr Crampton.* 
But not only is it identical with the coral limestone on the other side of 
the Firth, but it also presents a similar faunal assemblage to that found 
* “The Limestones of Aberlady, Dunbar, and St Monans,” Trans. Edin. Geol. Soc ., 
vol. viii, p. 374. 
Hurlet District. 
Top Marine Band . 
Top Hosie 
Main Hosie . 
Blackball Limestone 
Hurlet Limestone . 
