S72 Geological History of the Coast of Fife. [Sess. 
with the bones which should naturally be next to them in the 
complete skeleton. This is the celebrated Abden Bone-Bed 
which has formed the subject of valuable papers by Dr 
Traquair. The list may be given here ;—-ELASMOBRANCHII— 
Diplodus parvulus, Tristychius arcuatus, Huphyacanthus semi- 
striatus, Helodus falcatus, Oracanthus armigerus, Caliopristodus 
pectinatus, Cladodus mirabilis, C. sp., Acanthodes sp. TELEO- 
stomI—Rhizodopsis sp., Strepsodus striatulus, Megalichthys sp., 
Calacanthus abdenensis, Elonichthys pectinatus, Ewrynotus cre- 
natus, and Cheirodus crassus. 
Close above the shale which contains the Bone Bed is a thin 
band of what was formerly volcanic mud. In this a diligent 
search may be rewarded by the discovery of some interesting 
ferns, Rhacopteris inequilatera amongst others. Overlying this 
is a grey limestone, whose light colour stands out conspicuously 
against the sombre browns and russets of the associated 
volcanic rocks. Overlying the limestone comes a second fish 
bed (which cannot easily be got at), and on that lies another 
band of basalt lava, which forms part of the small headland 
known as Hoch-ma-toch. 
The history of this part of the series is of considerable 
interest. At the bottom below the Bone Bed is a lava flow. 
Then there is evidence of a local and apparently sudden 
destruction of a considerable number of fish (perhaps through 
some volcanic outbreak close by). Then a record of estuarine 
conditions, with the volcanic mud being washed into shallow 
water from the neighbouring volcano. To account for the 
presence of the limestone we must postulate a change of level 
probably taking place somewhat abruptly, and the existence of 
clear sea water, and, I think, of deep water too. On the sea 
floor was then slowly laid down what is part of a sheet of 
limestone, which, though not very thick, is part of a bed of 
rock which extended continuously to the south as far at least 
as Lancashire. I regard this limestone, which we may call 
No. 1, as the lower part of the Hurlet Limestone, which is so 
well known in the West of Scotland. I think that the 
average rate of formation of such a limestone as this, not 
allowing for pauses in deposition, may be one foot in 25,000 
1 See Trans. Geol. Soc. Edin. (vol. v. p. 810), and Proc, Geol. Assoc. (vol. xv. 
p. 143). 
