﻿DEVONO-SILUKLAST 
  formation. 
  201 
  

  

  only 
  one 
  " 
  Old 
  Eed 
  Sandstone 
  " 
  properly 
  so 
  called, 
  and 
  that 
  this 
  lies 
  

   at 
  the 
  top 
  of 
  the 
  Devonian, 
  and 
  immediately 
  below 
  the 
  base 
  of 
  the 
  

   Carboniferous, 
  series. 
  It 
  is 
  in 
  fact 
  the 
  upper 
  arenaceous 
  portion 
  of 
  

   the 
  Upper 
  Devonian 
  division. 
  All 
  other 
  so-called 
  " 
  Old 
  Eed 
  Sandstone" 
  

   formations 
  are 
  representatives 
  either 
  of 
  the 
  Middle 
  andLowerDevonian 
  

   beds 
  or 
  of 
  those 
  which! 
  propose 
  to 
  call 
  "Devono 
  -Silurian" 
  beds, 
  lying 
  

   on 
  the 
  confines 
  of 
  the 
  two 
  great 
  groups 
  each 
  of 
  which 
  bears 
  one 
  of 
  

   these 
  names. 
  Let 
  it 
  be 
  stated 
  once 
  for 
  all 
  that 
  the 
  only 
  formation 
  

   entitled 
  to 
  the 
  name 
  of 
  " 
  Old 
  Eed 
  Sandstone 
  " 
  is 
  that 
  which, 
  com- 
  

   posed 
  essentially 
  of 
  arenaceous 
  materials, 
  and 
  lying 
  immediately 
  below 
  

   the 
  base 
  of 
  the 
  Carboniferous 
  series 
  of 
  England 
  and 
  Wales, 
  Ireland, 
  

   Scotland, 
  and 
  the 
  continent, 
  is 
  known 
  and 
  described 
  as 
  follows 
  : 
  — 
  ■ 
  

  

  Localities 
  of 
  the 
  ; 
  ' 
  Old 
  Eed 
  Sandstone," 
  propekly 
  so 
  called. 
  

  

  (a) 
  Continental. 
  — 
  The 
  Psammites 
  die 
  Oondroz 
  (Lower 
  division 
  of 
  

   M. 
  Gosselet). 
  An 
  important 
  series 
  of 
  grey 
  and 
  reddish 
  sandstones, 
  

   grits, 
  and 
  subordinate 
  bands 
  of 
  shale, 
  of 
  which 
  the 
  upper 
  part 
  seems 
  

   to 
  graduate 
  into 
  the 
  Carboniferous 
  beds, 
  the 
  lower 
  to 
  be 
  connected 
  

   with 
  the 
  Upper 
  Devonian 
  series. 
  These 
  beds 
  are 
  largely 
  developed 
  

   in 
  Belgium, 
  and 
  are 
  of 
  marine 
  origin 
  *. 
  

  

  (b) 
  Devonshire. 
  — 
  The 
  PicJcwell-Down 
  Sandstone 
  of 
  !North 
  Devon, 
  

   surmounted 
  by 
  the 
  " 
  Upcot 
  Flags 
  " 
  ( 
  = 
  Kiltorcan 
  beds). 
  An 
  important 
  

   series 
  of 
  sandstones 
  and 
  grits, 
  grey 
  below, 
  red 
  and 
  purple 
  above, 
  

   lying 
  below 
  the 
  base 
  of 
  the 
  Carboniferous 
  series 
  (the 
  Baggy 
  and 
  

   Marwood 
  beds 
  with 
  Oucullcea 
  and 
  Adiantites), 
  and 
  above 
  the 
  " 
  JVIort- 
  

   hoe 
  slates. 
  Mr. 
  Champernowne 
  has 
  identified 
  this 
  sandstone 
  in 
  

   South 
  Devon. 
  

  

  The 
  view 
  that 
  the 
  Pickwell-Down 
  Sandstone 
  is 
  the 
  true 
  repre- 
  

   sentative 
  of 
  the 
  Old 
  Eed 
  Sandstone 
  of 
  the 
  South 
  of 
  Ireland 
  has 
  re- 
  

   ceived 
  the 
  sanction 
  of 
  the 
  President 
  of 
  the 
  Geological 
  Society 
  in 
  his 
  

   recent 
  elaborate 
  address 
  f 
  . 
  

  

  (c) 
  South 
  Wales 
  and 
  Hereford 
  §c. 
  — 
  Yellow 
  Sandstone 
  and 
  Con- 
  

   glomerate 
  of 
  De 
  la 
  Beche. 
  A 
  thick 
  series 
  of 
  yellow 
  grits, 
  sand- 
  

   stones, 
  and 
  conglomerate 
  beds, 
  lying 
  immediately 
  below 
  the 
  " 
  Lower 
  

   Limestone 
  shale," 
  and 
  above 
  the 
  great 
  series 
  of 
  red 
  sandstones 
  and 
  

   marls 
  with 
  " 
  Cornstones 
  " 
  (Estuarine 
  Devonian). 
  These 
  beds 
  are 
  

   undoubtedly 
  in 
  the 
  position 
  of 
  the 
  Pickwell-Down 
  Sandstone 
  south 
  

   of 
  the 
  Bristol 
  Channel, 
  and 
  ought 
  to 
  be 
  separated 
  in 
  geological 
  maps 
  

   from 
  the 
  underlying 
  beds, 
  which 
  represent 
  the 
  Devonian 
  series 
  of 
  the 
  

   same 
  district. 
  

  

  (d) 
  Ireland. 
  — 
  Grey, 
  yellow, 
  and 
  reddish 
  flagstones 
  and 
  shales, 
  

   with 
  fishes, 
  also 
  with 
  Anodonta 
  Jukesii 
  and 
  plants 
  (Adiantites 
  hiber- 
  

   nicus) 
  &c. 
  (Kiltorcan 
  beds), 
  passing 
  down 
  into 
  red 
  sandstone 
  and 
  

   conglomerate 
  at 
  base, 
  everywhere 
  unconformable 
  to 
  the 
  beds 
  on 
  

   which 
  they 
  rest, 
  as 
  shown 
  by 
  Sir 
  E. 
  Griffith. 
  In 
  thickness 
  from 
  

  

  * 
  These 
  beds 
  have 
  also 
  yielded 
  plants, 
  and 
  amongst 
  others 
  " 
  Palesopteris 
  (Adi- 
  

   antites) 
  hibernica 
  " 
  (Mourlon, 
  ' 
  Geol. 
  de 
  la 
  Belgique,' 
  p. 
  88). 
  

  

  t 
  Quart, 
  Journ. 
  Geol. 
  Soc. 
  vol. 
  xxxvii. 
  p. 
  192. 
  In 
  the 
  flagstones 
  at 
  the 
  top 
  of 
  

   these 
  beds 
  the 
  Adiantites 
  has 
  been 
  found, 
  as 
  stated 
  by 
  Mr. 
  JEtheridge, 
  who 
  does 
  

   not 
  yet 
  despair 
  of 
  finding 
  Anodonta. 
  May 
  this 
  hope 
  be 
  realized 
  ! 
  

  

  p2 
  

  

  