62 Dr. J. FE. Marr—The Ashgillian Series. 
an asterisk. Among these are Caryocystites Davisii and Staurocephalus 
clavifrons. As both limestone and shales are developed in the quarry 
of the typical locality, Ashgill, it seems peculiarly appropriate, in the 
absence of any accurate definition of the limits of the so-called Upper 
Bala Beds, to use the name of this locality in connection with the 
division, as I suggested in my Address to the Geological Society 
in 1905. 
In 1892 (Got. Mae., Dec. I11, Vol. IX, p. 97) I published a 
paper on ‘‘ The Coniston Limestone Series.’ In this paper separate 
lists of the Stawrocephalus Limestone and Ashgill Shale divisions of 
the Ashgillian are given, but the Keisley Limestone fossils are 
wrongly placed with the Caradocian fossils of the Sleddale group. 
The true age of this Keisley Limestone was proved by Mr. F. R. 
Cowper Reed.’ In his two papers on this limestone he shows that 
its fauna appertains to the Upper Bala (Ashgillian), and not to the 
Middle Bala (Caradocian). 
Last year 1 was able to show that the Stauwrocephalus Limestone of 
the Cross Fell Inlier, previously described by Professor Nicholson and 
myself, was im the Keisley Limestone and not above it as we had 
wrongly concluded. The Ashgillian Beds of the North of England are 
therefore separable into two divisions— 
Ashguill Shales. 
Staurocephalus Limestone (with Keisley Limestone). 
Turning now to South Wales, we find the most satisfactory 
development of Ashgillian Beds, so far as Britain is concerned, in 
that area. These beds were classified and described by the late 
Mr. T. Roberts and myself in 1885 in a paper in the Quarterly Journal 
of the Geological Society (vol. xli, p. 476). We divided the beds 
as follows :— 
Slade Calcareous Shales. 
Redhill Shales. 
Sholeshook Limestone. 
We also showed that the Sholeshook Limestone was comparable 
with the Staurocephalus Limestone of Lakeland, the Rhiwlas Lime- 
‘stone of the Bala area, and other deposits elsewhere, and that the 
Redhill Beds were comparable with the Ashgill Shales. The Slade 
Beds presented lithological characters differing from those of other 
known areas possessing Ashgillian rocks, and there is still some 
uncertainty concerning their equivalents elsewhere, and accordingly 
we are yet uncertain as to the precise position of the line marking the 
top of the Ashgillian Beds of some districts. To this point I shall 
recur later. 
In this paper sufficient fossil lists were given to show the marked 
difference between the fauna of the Caradoc Beds and that of the 
overlying Ordovician strata, and the latter were shown to be widely 
spread in the British Isles and to be represented by beds containing 
similar faunas on the Continent, although the equivalence of some of 
the Scandinavian beds with the beds of Ashgill had previously been 
asserted by one of the authors and likewise by Dr. 8. L. Tornquist. 
1 Q.J.G.8., vol. lii, p. 407, and vo!. liu, r. 67. 
