254 Proceedings of the Royal Physical Society. 
Limestone of the West of Scotland. The beds containing this succession of 
faunas in such small thickness constitute the well-known Alum Shale which 
was formerly so extensively worked in the Campsie district. If Mr Macnair 
establishes his contention that these three successive faunas are confined to 
this horizon, it will afford a splendid datum line for correlating the beds in 
East and West Scotland. 
Dr Crampton has identified the first Abden Limestone with the Long 
Craig Limestone of Aberlady and Dunbar. 
Another interesting study can be made of a peculiar succession of beds, 
where, in the short compass of about 10 feet of strata, there is represented 
the phases of a passage from a land surface to clear sea conditions. The 
section occurs where the second Abden Limestone crops out on the Fife 
shore, east of Kinghorn. Overlying the last of the basalt Java flows of the | 
Burntisland volcanic plateau is a bed of ash or tuff, which, near its top, 
contains well-preserved fronds of Rachopteris duplex almost perfect, doubtless 
trapped either upon or near a land surface. The ash towards its top assumes the 
appearance of one of the oil-shale “ Marls” and passes upwards into a fireclay. 
This is succeeded by a band about an inch thick, crammed with the large 
and strong shells of Nazadites (Myalina) crassa, an estuarine form. The shell 
bed is succeeded by about 4 feet of hard black shale which contains, in 
addition to Naiadites, Bellerophon and Ortheceras, indicating more saline 
conditions. The next 4 feet of blue calcareous shale is crowded with 
Productus longispinus, orthids, aviculopectens, Lingula, Orbiculoidea, Nucula 
aud Macrochilina, as well as debris of crinoids, marking a distinctly marine. 
though muddy condition. Above comes the main mass of the second Abden 
Limestone, about 14 feet thick, a white limestone almost free from terrigenous 
sediment, arranged in layers, from about a foot to less than an inch in 
thickness, marking a clear sea deposit formed from organic remains only, 
The organisms themselves are assorted in distinct colonies or layers and do’ 
not occur promiscuously throughout the limestone. Near the base are found 
Productus, crinoids, and simple corals. Above this, there are lines of reef- 
building colonies of Lithostrotion junceum and L. irregulare and matted 
masses of Stenopora (Chetetes). Towards the middle of the band there are 
thin flags made up almost entirely of the broken-up plates, spines, and_ 
lanterns of Archwocidaris, and, near the top of the seam, bands of more 
muddy limestone with debris of encrinites alternate with the flaggy white: 
layers, as if sediments were being pushed out from the land and were 
invading the former clear sea. In the 100 feet of sediments which separate 
this band from the overlying Seafield Tower or Invertiel Limestone there are 
two seams of coal, a fact which would seem to indicate that the second Abden 
