183 
1916-17.] The Hurlet Sequence and the Abden Fauna. 
in the centre. There can be no doubt as to the identity of the respective 
limestones, and the section throws much additional light upon the nature 
of the sequence between the Hollybush and Hurlet Limestones. Unfortu- 
nately the strata immediately underlying the Hurlet Limestone is not 
exposed in this section, and the existence of the Alum Shale fauna cannot 
be determined. 
Another important section is that exposed in the burn at Meikle 
Corseford, Howood, about 8 miles to the west of Hurlet. Immediately 
below the Hurlet Limestone in this section comes the Alum Shale position, 
which has yielded a somewhat remarkable faunal association, and which 
seems to be of considerable significance. The fossils, which are exceedingly 
numerous, though somewhat crushed, are principally brachiopods and 
lamellibranchs. Of the former, the most common are Schizophoria 
resupinata and Productus semireticulatus. The most abundant lamelli- 
branchs are Sanguinolites abdenensis, Streblopteria ornata, Actinopterici 
persulcata, and Myalina verneuili , the brachiopod band when clearly 
defined lying above the lamellibranch band. Now we shall show that 
these four lamellibranchs occur in association on exactly the same strati- 
graphical horizon in the Campsie district and at Corrieburn, also that they 
can be traced from Cobbinshaw through the Bathgate Hills to Charlestown 
on the Firth of Forth, and thence into the east of Fife and over the 
Lothians as far as Dunbar. The stratigraphical significance of this 
fauna in the Alum Shale will be discussed in more detail in a future part 
of this paper. 
Another important section confirming the sequence in the Lower Lime- 
stone Series of this district is that seen in the Gryffe Water, between the 
Bridge of Weir and Crosslee. These sections have been described by me in 
detail in a series of papers * published in the Transactions of the Geo- 
logical Society of Glasgoiv, to which the reader is referred. The Alum 
Shale is now covered up, but fragments containing the fauna can be 
picked up on the bings. 
V. Sections between Campsie and Kilsyth. 
In tracing the Hurlet Sequence into the Fife district and the East 
of Scotland we proceed in the first instance by the way of those 
sections which lie between Campsie and Kilsyth, and, as we shall see, 
they afford a remarkable amount of evidence bearing upon the correla- 
tion of the Lower Limestone Series in the East of Scotland with that of 
* Trans. Geol. Soc. Glasgow , vol. xv, p. 215. 
