466  CAERNARVONSHIRE  EELSITES  AND  CONGLOMERATES.  [Aug.  1 893, 
Prof.  Hughes  thought  that  the  difficulty  of  following  a  contro¬ 
versial  paper  like  that  before  them  was  unnecessarily  increased  by 
the  manner  in  which  it  had  been  presented,  with  maps  on  which  no 
dips  were  shown,  and  sections  to  which  no  reference-index  was 
given.  He  protested  also  against  the  use  of  old  familiar  names  in 
new  senses.  So  far  as,  from  his  own  knowledge  of  the  ground,  he 
was  able  to  follow  the  Author’s  remarks,  he  could  not  agree  with 
his  conclusions,  and  was  unable  to  endorse  the  accuracy  of  the 
observations  on  those  parts  of  the  area  on  which  the  Author  said  he 
chiefly  relied  for  establishing  them. 
Hr.  Putney  said  that  those  points  in  the  paper  which  appeared 
to  him  to  be  open  to  doubt  were  the  determination  of  some  of  the 
felsites  and  the  order  of  succession  of  certain  beds.  Such  doubt 
probably  resulted  from  the  Author’s  treatment  of  his  subject.  The 
frequent  association  of  grit-bands  with  slates  rendered  it  possible 
that  some  of  the  so-called  felsites  might  be  felspathic  grits,  which 
often  resembled  felsites.  It  was  to  be  hoped  that  Prof.  Blake  would 
examine  the  doubtful  rocks  microscopically,  and  embody  his  results 
in  another  paper.  The  high  angles  at  which  some  of  the  beds 
dipped  indicated  that,  in  certain  cases,  a  slight  inclination  on  one 
or  other  side  of  the  vertical  would  materially  affect  conclusions  as  to 
stratigraphical  sequence. 
Mr.  Marr  also  spoke. 
The  Author,  in  reply,  said  he  hoped  he  understood  the  President 
aright  to  say  that  he  did  not  believe  in  any  pre-Cambrian  rock  in  the 
district  discussed.  He  admitted  that  under  the  general  term  4  felsite  ’ 
he  included  any  of  its  clastic  accompaniments,  and  the  term  4  post- 
Cambrian  ’  was  used  in  a  special  sense,  meaning  only  later  than  the 
Purple  Slates. 
