64 Dr. J. EH. Marv—The Ashgillian Series. 
doubt as to the correctness of this correlation, in which case the over- 
lying Ladyburn Mudstones are the probable equivalents of the Ashgill 
Shales. 
It must be borne in mind that as there is stratigraphical conformity 
between the Ordovician Hartfell Shales and Silurian Birkhill Shales 
of the Moffat area, the uppermost portion of the graptolite-bearing 
Hartfell Shales must also be referable to the Ashgillian Series. 
In Ireland beds of Ashgillian age have been detected in various parts. 
In 1896 Messrs. Gardiner & Reynolds’ described the limestone of 
the Chair of Kildare, which with previous writers they. refer to the 
Coniston Limestone, and in 1897 the same authors? describe, among 
other rocks, the Portraine Limestone, and state that it is comparable 
to the Chair of Kildare Limestone on the one hand and on the other to 
the Keisley and Sholeshook Limestones of Great Britain. Each of 
these deposits, therefore, belongs to the Ashgillian Series. 
But the most interesting Irish development of Ashgillian age is 
found near Pomeroy. ‘The fauna of these rocks has long been known, 
having been described in 1863 in Portlock’s ‘‘ Report on the Geology 
Ofgelondondennyaar . Tyrone, and Fermanagh.” 
In our paper on Haverfordwest Mr. Roberts and I state that the 
group of fossils characteristic of the Sholeshook Limestone ‘‘ appears 
to occur at Desertcreat{e |], Tyrone,” and we enumerate species common 
to the South Welsh and Irish areas, and state that fossils from the 
Irish locality seem to show that the representatives of the Redhill 
stage occur there also. 
Recently this tract has been studied by a party of Cambridge 
geologists, and an outline of their results has been published in the 
Gxoroetcat Magazine by Mr. W. G. Fearnsides.* The beds referred 
to the Ashgillian Series are there spoken of as the Desertcreate Group. 
It shows the Drummuck facies, and the point of particular interest is 
the discovery of graptolites of Upper Hartfell age associated with 
fossils characteristic of the non-graptolitic facies of Ashgillian deposits. 
The subdivisions of the Desertcreate Group will be found on p. 422 of 
Mr. Fearnsides’ notice, and need not be repeated here. 
Abroad the representations of the Ashgillian Series are known only 
in Scandinavia and Russia. In 1879 8. L. Tornquist,* who had 
examined my specimens of Ashgill fossils and afterwards was taken 
over the Lake District section by my brother, correlated the Ashgill 
Shales with the ‘ Brachiopod-schists’ of Sweden, and in 1882 ° 
I pointed out that they were comparable with the lower part only 
of these Brachiopod - schists. Later in our Haverfordwest paper 
Mr. Roberts and I showed that both Staurocephalus Limestone and 
Ashgill Shales were represented in Sweden. 
The Leptena Limestone of Dalarne has been referred to various 
horizons, but Schmidt’s work in the Baltic provinces has shown that 
it is clearly equivalent to stage F of Russia, and it must therefore be 
1Q.J.G.8., vol. li, p. 587. 
2 Q.J.G.S., vol. liii, p. 620. 
° Grou. Mac., Dec. V, Vol. III, p. 421. 
4 Ofv. af k. Vistar, Akad: Forhandl. , P- 63. 
5 Q.J.G.8., vol. xxxviil, p. 313. 
