Johns: The Yoredale and Pendleside Series. 13 
Ingleborough. Here, therefore, are three sections in the 
Yoredale area where the Pendleside fauna occurs in beds of 
Yoredale age. To confine the discussion to areas that can or 
have been correlated with the succession in north-west York- 
shire, it might be mentioned that Prof. Lebour, and later Mr. 
Stanley Smith, has noted the occurrence of P. becheri in Nor- 
thumberland in beds again of Yoredale age below the level of 
the Great (Main of Ingleboro’) Limestone, while in Scotland 
P. bechert has been found* in the Lower Limestone Series. The 
evidence is therefore always consistent, and it would appear 
that the establishment of P. becheri has a definite time value. 
There is, however, negative evidence which cannot be over- 
looked in this discussion. Despite persistent search, no in- 
dication of the occurrence of the Pendleside fauna from beds 
that can be demonstrated to lie above the Main or Cam Lime- 
stone has ever been found. Dr. Hind has himself more than 
once called attention to this, and the importance of the failure 
must be insisted upon. 
The faunal evidence is therefore clear; the Pendleside 
fauna has been found in rocks of Lower Yoredale age. It 
has never been found in beds above the Main Limestone. 
Therefore, even if Phillips’ restricted definition of the Yoredale 
series be employed, the evidence points to the equivalence of 
Yoredales and Pendlesides. If the definition of the Geological 
. Survey be accepted, as it is in this paper, then the Pendleside 
Series must of necessity be the time equivalent of some parts 
of the Yoredales, unless it is suggested that there is a non- 
sequence at this important level throughout an area covering 
hundreds of square miles, which would be unthinkable. The 
view that the Pendleside Series is younger than the Yoredales 
is full of difficulties. That it succeeds the Visean which 
commonly has a Cyathaxonia phase at the summit, is the 
experience of most workers. There is throughout the Yoredale 
area a Cythaxonia phase at the top of the Great Scar Limestone. 
The Upper Yoredale Limestones contain a coral fauna which 
is higher in development than the D, of Bristol; yet this D, 
represents the top of the Visean in that typical area. It will 
be remembered that the Belgian geologists who visited Ingle- 
borough declined to include the Main (Upper Yoredale) Lime- 
stone in their zone of P. giganteus, though their reasons were 
perhaps not very convincing at the time. 
It was on these grounds that the writer proposed} a new 
classification of the Lower Carboniferous Rocks which would 
give due weight to this evidence, and at the same time do justice 
to the many workers who have contributed to our knowledge. 
* The evidence has not yet been published. 
7+ Geol. Mag., 1910, p. 562. 
