﻿PE0P. 
  C. 
  LAl'WOETH 
  ON 
  THE 
  GTEVAN 
  SUCCESSION. 
  625 
  

  

  The 
  Mulloch-Hill 
  beds, 
  as 
  thus 
  extended, 
  consist 
  therefore 
  of 
  the 
  

   following 
  members 
  : 
  — 
  

  

  Cab. 
  Glenwells 
  Grap 
  tori 
  tic 
  Mudstones 
  and 
  Flags. 
  

   Ca 
  2 
  . 
  Kough-Neuk 
  or 
  Mulloch-Hill 
  Sandstones. 
  

   Oa 
  1 
  . 
  Mulloch-Hill 
  Conglomerate. 
  

  

  Generally 
  speaking, 
  it 
  may 
  be 
  said 
  that 
  their 
  lower 
  beds 
  are 
  thicker 
  

   and 
  contain 
  more 
  of 
  the 
  purple 
  and 
  grey 
  tilestones 
  ; 
  the 
  middle 
  beds 
  

   are 
  alternations 
  of 
  thick-bedded 
  sandy 
  flags 
  and 
  sandy 
  shales 
  ; 
  and 
  

   the 
  upper 
  beds 
  show 
  man}~ 
  zones 
  of 
  soft 
  mudstones, 
  pale-hearted 
  and 
  

   weathering 
  to 
  a 
  golden 
  yellow. 
  

  

  The 
  entire 
  sequence 
  is 
  exposed 
  along 
  the 
  line 
  of 
  section 
  already 
  

   given 
  (fig. 
  22). 
  The 
  thick-bedded 
  sandstones 
  are 
  laid 
  open 
  in 
  many 
  

   spots 
  to 
  the 
  left 
  of 
  that 
  line 
  in 
  the 
  broad 
  hollow 
  separating 
  Quarrel 
  

   Hill 
  from 
  the 
  Mulioch 
  Quarries. 
  The 
  flaggy 
  central 
  (or 
  Kough-Neuk 
  

   beds) 
  occur 
  in 
  the 
  quarries 
  on 
  the 
  roads 
  to 
  the 
  south 
  of 
  Mulioch, 
  and 
  

   the 
  highest 
  yellow 
  pale-Tiearted 
  flaggy 
  mudstones 
  near 
  the 
  house 
  of 
  

   High 
  Xewlands. 
  

  

  Fossils 
  occur 
  throughout 
  the 
  group, 
  but 
  they 
  are 
  comparatively 
  

   rare 
  in 
  its 
  highest 
  division. 
  In 
  the 
  exposures 
  of 
  the 
  lower 
  division, 
  

   in 
  the 
  depression 
  and 
  roadway-quarries 
  west 
  of 
  Mulioch 
  Hill, 
  they 
  

   occur 
  in 
  incredible 
  profusion, 
  mainly, 
  however, 
  in 
  the 
  form 
  of 
  casts, 
  

   the 
  shell 
  itself 
  being 
  weathered 
  away 
  and 
  replaced 
  by 
  a 
  soft 
  ochreous 
  

   matter 
  of 
  a 
  beautiful 
  orange-yellow 
  colour. 
  Here 
  occur 
  in 
  abun- 
  

   dance 
  such 
  characteristic 
  forms 
  as 
  Atrypa 
  hemisplicerica, 
  Orthis 
  

   reversa, 
  Meristella 
  ungiistifrons, 
  and 
  Rliynchonella 
  cuneata, 
  together 
  

   with 
  crowd 
  of 
  others, 
  of 
  which 
  the 
  most 
  remarkable 
  is 
  the 
  enigma- 
  

   tical 
  Nidulites 
  favus, 
  which 
  was 
  first 
  described 
  from 
  this 
  localny. 
  

  

  In 
  some 
  of 
  the 
  lower 
  beds 
  the 
  shells 
  abound 
  to 
  such 
  an 
  extent 
  that 
  

   the 
  rock 
  deserves 
  rather 
  the 
  title 
  of 
  an 
  impure 
  limestone 
  than 
  that 
  of 
  

   a 
  true 
  sandstone. 
  This 
  is 
  the 
  case 
  also 
  with 
  the 
  succeeding 
  central 
  

   and 
  more 
  flaggy 
  group, 
  of 
  which 
  a 
  deep 
  section 
  is 
  shown 
  in 
  the 
  old 
  

   quarry 
  of 
  Rough 
  Xeuk, 
  one 
  of 
  the 
  most 
  prolific 
  spots 
  for 
  fossils 
  in 
  the 
  

   Girvan 
  district. 
  Corals 
  are 
  perhaps 
  more 
  abundant 
  in 
  this 
  part 
  of 
  

   the 
  subgroup 
  than 
  in 
  the 
  beds 
  below 
  ; 
  but 
  even 
  here, 
  as 
  throughout 
  

   the 
  whole 
  series, 
  Brachiopoda 
  are 
  overwhelmingly 
  preponderant. 
  

  

  (ii.) 
  Pentamer 
  us- 
  Grits 
  and 
  Shales 
  of 
  Newlands. 
  

  

  It 
  will 
  be 
  apparent 
  on 
  a 
  study 
  of 
  the 
  map 
  and 
  sections 
  (PI. 
  XXV 
  . 
  4), 
  

   that 
  these 
  Mulloch-Hill 
  beds 
  form 
  a 
  well-marked 
  zone, 
  which 
  crosses 
  

   the 
  great 
  inlier 
  from 
  side 
  to 
  side, 
  reposing 
  on 
  the 
  Ardmillan 
  group 
  

   of 
  the 
  central 
  areas, 
  and 
  throwing 
  off 
  a 
  fresh 
  series 
  of 
  beds, 
  which 
  

   occur 
  only 
  in 
  the 
  north-easterly 
  angle 
  of 
  the 
  inlier 
  in 
  the 
  neigh- 
  

   bourhood 
  of 
  the 
  farmstead 
  of 
  Xewlands 
  and 
  the 
  woods 
  of 
  Glen- 
  

   shalloch. 
  It 
  will 
  be 
  evident 
  also 
  on 
  further 
  study, 
  that 
  the 
  depo- 
  

   sition 
  of 
  these 
  new 
  beds 
  upon 
  the 
  ground 
  is 
  conclusive 
  of 
  their 
  

   superiority 
  to 
  the 
  Mulloch-Hill 
  rocks 
  ; 
  for 
  they 
  constitute 
  a 
  definite 
  

   zone, 
  having 
  the 
  same 
  strike 
  as 
  the 
  Mulloch-Hill 
  beds 
  themselves, 
  

   and 
  forming 
  an 
  exterior 
  coating 
  to 
  the 
  latter, 
  as 
  do 
  the 
  Mulloch- 
  

   Hill 
  beds 
  to 
  the 
  underlying 
  rocks 
  of 
  the 
  Ardmillan 
  group. 
  In 
  

   developing 
  the 
  interrelations 
  of 
  the 
  subformations 
  composing 
  the 
  

  

  