﻿202 
  PKOF. 
  E. 
  HULL 
  ON 
  A 
  PEOPOSED 
  

  

  2000 
  to 
  3000 
  feet, 
  but 
  (owing 
  to 
  overlapping 
  of 
  the 
  Carboniferous 
  

   beds) 
  sometimes 
  entirely 
  wanting 
  in 
  the 
  south-west 
  of 
  Ireland 
  *. 
  

  

  In 
  the 
  north 
  of 
  Ireland 
  these 
  beds 
  are 
  represented 
  in 
  the 
  Curlew 
  

   Hills 
  and 
  along 
  the 
  north 
  shore 
  of 
  Clew 
  Bay, 
  &c. 
  

  

  (e) 
  Scotland. 
  — 
  At 
  the 
  base 
  in 
  Haddingtonshire 
  and 
  Berwickshire 
  

   it 
  consists 
  of 
  a 
  lower 
  portion 
  of 
  brecciated 
  conglomerate, 
  and 
  of 
  an 
  

   upper 
  series 
  of 
  red 
  sandstones 
  and 
  marls, 
  containing 
  Cyclojptems 
  

   (Palceopteris), 
  Bothriol&pis, 
  &c, 
  passing 
  into 
  the 
  base 
  of 
  the 
  Calci- 
  

   ferous 
  Sandstone 
  series. 
  To 
  these 
  upper 
  beds 
  the 
  Dura-Den 
  sand- 
  

   stone 
  with 
  fishes 
  belongs 
  ; 
  it 
  is 
  probably 
  on 
  the 
  horizon 
  of 
  the 
  

   Kiltorcan 
  beds 
  of 
  Ireland. 
  

  

  All 
  the 
  above 
  beds 
  are, 
  I 
  believe, 
  representative 
  in 
  time 
  of 
  each 
  

   other 
  and 
  of 
  the 
  true 
  Old 
  Bed 
  Sandstone, 
  and 
  precede 
  the 
  lowest 
  

   Carboniferous 
  strata, 
  which 
  are 
  essentially 
  of 
  marine 
  origin 
  f. 
  The 
  

   fish-remains 
  from 
  the 
  beds 
  of 
  this 
  group 
  are 
  different 
  in 
  the 
  main 
  

   from 
  those 
  of 
  the 
  (so-called) 
  Lower 
  Old 
  Bed 
  Sandstone 
  of 
  Scotland 
  : 
  

   and, 
  according 
  to 
  Mr. 
  Etheridge, 
  no 
  genera 
  or 
  species 
  of 
  fish 
  pass 
  

   into 
  the 
  Carboniferous 
  beds 
  %. 
  Their 
  lacustrine 
  origin 
  is 
  attested 
  

   by 
  the 
  presence 
  of 
  Anodonta 
  both 
  in 
  the 
  south 
  of 
  Ireland 
  and 
  (as 
  

   Prof. 
  Lebour 
  has 
  shown) 
  at 
  the 
  base 
  of 
  the 
  Lower 
  Carboniferous 
  

   sandstones 
  of 
  Northumberland. 
  On 
  the 
  other 
  hand, 
  the 
  lacustrine 
  

   conditions 
  of 
  the 
  British 
  Isles 
  seem 
  to 
  have 
  given 
  place 
  to 
  those 
  of 
  a 
  

   pelagic 
  character 
  over 
  the 
  Continental 
  area 
  adjoining. 
  

  

  Having 
  thus 
  endeavoured 
  to 
  show 
  what 
  beds 
  properly 
  represent 
  

   the 
  Old 
  Bed 
  Sandstone, 
  and 
  their 
  true 
  position 
  in 
  the 
  geological 
  

   series, 
  I 
  proceed 
  to 
  describe 
  briefly 
  those 
  referable 
  to 
  the 
  formation 
  

   I 
  propose 
  to 
  call 
  " 
  Devono-Silurian." 
  

  

  Localities 
  of 
  the 
  Devono-Silurian 
  Formation. 
  

  

  As 
  already 
  stated, 
  the 
  strata 
  represented 
  by 
  the 
  above 
  title 
  lie 
  at 
  

   the 
  confines 
  of 
  the 
  two 
  great 
  groups 
  bearing 
  these 
  names 
  respectively. 
  

  

  Though 
  they 
  are 
  in 
  some 
  places 
  known 
  by 
  the 
  name 
  of 
  " 
  Old 
  

   Bed 
  Sandstone," 
  with 
  or 
  without 
  the 
  prefix 
  of 
  " 
  Lower/' 
  they 
  are 
  in 
  

   reality 
  separated 
  by 
  a 
  wide 
  interval 
  of 
  geological 
  time 
  from 
  the 
  Old 
  

   Bed 
  Sandstone 
  properly 
  so 
  called. 
  This 
  interval 
  (as 
  I 
  have 
  shown 
  

   in 
  papers 
  already 
  published) 
  finds 
  its 
  record 
  in 
  the 
  Lower, 
  Middle, 
  

   and 
  partly 
  in 
  the 
  Upper 
  Devonian 
  series 
  — 
  that 
  is 
  to 
  say, 
  in 
  all 
  those 
  

   marine 
  strata 
  which 
  in 
  Devonshire 
  lie 
  between 
  the 
  " 
  Pickwell- 
  

   Down 
  Sandstone" 
  above 
  and 
  the 
  "Foreland 
  Grits 
  and 
  Slates" 
  be- 
  

   low, 
  containing 
  195 
  genera 
  and 
  544 
  species 
  of 
  marine 
  forms, 
  of 
  

   which 
  only 
  32 
  genera 
  and 
  51 
  species 
  pass 
  into 
  the 
  Carboniferous 
  

   group 
  §. 
  I 
  mention 
  this 
  on 
  the 
  authority 
  of 
  Mr. 
  Etheridge, 
  in 
  

  

  * 
  Proc. 
  Koyal 
  Dublin 
  Soc. 
  vol. 
  i. 
  new 
  ser. 
  (1880), 
  pp. 
  135-150. 
  

  

  t 
  Quart. 
  Journ. 
  Geol. 
  Soc. 
  vol. 
  xxxiii. 
  p. 
  616 
  &c. 
  I 
  am 
  uncertain 
  whether 
  these 
  

   beds 
  may 
  not 
  include 
  a 
  portion 
  of 
  the 
  Lower 
  Calciferous 
  Sandstone 
  of 
  the 
  Clyde, 
  

   which 
  is 
  not 
  unlike 
  the 
  Old 
  Eed 
  Sandstone 
  of 
  the 
  Curlew 
  Hills 
  &c. 
  in 
  Ireland. 
  

  

  % 
  Anniversary 
  Address. 
  Quart. 
  Journ. 
  Geol. 
  Soc. 
  vol. 
  xxxvii. 
  p. 
  195. 
  

   Coccosteus 
  is 
  the 
  most 
  abundant 
  of 
  the 
  fishes 
  from 
  the 
  Kiltorcan 
  beds 
  of 
  

   Ireland. 
  

  

  § 
  Etheridge, 
  Quart. 
  Journ. 
  Geol. 
  Soc. 
  vol. 
  xxxvii. 
  p. 
  197. 
  As 
  Mr. 
  Etheridge 
  

   has, 
  in 
  his 
  Presidential 
  Address, 
  given 
  his 
  sanction 
  to 
  the 
  views 
  I 
  have 
  put 
  for- 
  

  

  