HUGHES : INGLEBOROUGH. 
73 
appearance, and they had not yet distinguished their Graptolitic 
Mudstone into which the Coniston Flags pass down, from the 
Ashgill or Fairy Gill Shales, into which the Coniston Limestone 
passes up, and Sedgwick's " separation of the so-called Caradoc 
Sandstone into two distinct groups, viz., (1) May Hill Sandstone ; 
(2) Caradoc Sandstone," proposed to the Geological Society 
in 1852* had not yet been accepted. 
Harkness and Nicholson therefore thought that the result 
of their researches was " to add a great thickness of strata to 
the highest member of the Lower Silurian rocks." 
Murchison was, of course, not unwilling to accept this view, 
and when the members of the Geological Survey commenced 
work in the north of England the Coniston Grits were officially 
considered to be the equivalent of the Caradoc Sandstone. 
Now it was stated as part of the evidence for the Llandeilo 
or at all events Lower Silurian age of the Graptolitic Mudstones, 
that among the strata which were associated with the Grap- 
tolitic Shales in Ireland, Cardiola interrupta was met with, ib., 
p. 302, and it was a common fossil in the Coniston Flags and 
Grits which were held to be of Caradoc age, and therefore Cardiola 
interrupta was a lower Silurian and even Llandeilo fossil. 
Mr. Etheridge, palaeontologist to the Survey, entered it 
as such in his lists. 
On this authority Barrande accepted Cardiola interrupta 
as a Lower Silurian Form. 
Defense des Colonies V. 
Apparition et reapparition en Angleterre et en 
Ecosse des especes coloniales Siluriennes de la Boheme, 
d'apres les documents Anglais les plus authentiques 
et les plus recents. 188L 
" Anjourd'hui, I'extension verticale de Cardiola interrupta, 
dans les regions typiques siluriennes, est constatee par des 
documents, que nons exposons in extenso dans notre vol vi., 
Acephales, p. 46., in 4to et. dans notre Extrait in 8vo, p. 72, 
qui vont etre publies. 
* Q.J.G.S., vol.ix., 1853. 
