﻿PROP. 
  C. 
  LAPWORTH 
  ON 
  THE 
  GIRVAN 
  SUCCESSION. 
  649 
  

  

  of 
  shells 
  of 
  Atrypa 
  reticularis 
  and 
  StropJiomena, 
  and 
  the 
  dark-striped 
  

   shales 
  to 
  the 
  north 
  well-preserved 
  specimens 
  of 
  

  

  Eastrites 
  maximus, 
  Carr. 
  Monograptus 
  Hisingeri, 
  Barr. 
  

   Monograptus 
  crassus, 
  Lapw. 
  Diplograptus 
  palmeus, 
  Barr. 
  

   turriculatus, 
  Barr. 
  Peltocaris 
  aptychoides, 
  Salt. 
  

  

  Here 
  the 
  strata 
  of 
  this 
  zone 
  make 
  their 
  final 
  appearance 
  in 
  the 
  

   Girvan 
  region, 
  heing 
  buried 
  from 
  sight 
  a 
  few 
  yards 
  to 
  the 
  eastward 
  

   by 
  the 
  unconformably 
  overlying 
  Old 
  Red 
  Sandstone 
  of 
  Maxwellston 
  

   Hill. 
  

  

  I 
  regard 
  this 
  Camregan 
  zone, 
  which 
  has 
  formed 
  our 
  chief 
  horizon 
  

   of 
  reference 
  among 
  the 
  complicated 
  group 
  of 
  Graptolitic 
  shales 
  

   and 
  flags, 
  conglomerates, 
  gritstones, 
  and 
  calcareous 
  rocks 
  developed 
  

   in 
  Penwhapple 
  Glen, 
  Saugh 
  Hill, 
  and 
  upon 
  the 
  outer 
  edges 
  of 
  the 
  

   coast-platform 
  near 
  Woodland, 
  as 
  forming 
  the 
  final 
  member 
  of 
  

   the 
  Third 
  Series 
  of 
  rock-formations 
  into 
  which 
  the 
  Girvan 
  succes- 
  

   sion 
  is 
  most 
  naturally 
  divided. 
  This 
  series, 
  which 
  commences 
  

   with 
  the 
  Mulloch-Hill 
  conglomerate, 
  and 
  terminates 
  with 
  the 
  

   upper 
  grit 
  bands 
  of 
  these 
  Camregan 
  beds, 
  is 
  nowhere 
  completely 
  

   exhibited 
  from 
  base 
  to 
  summit 
  in 
  continuous 
  section 
  in 
  the 
  Girvan 
  

   region 
  ; 
  and 
  the 
  order 
  of 
  its 
  sediments 
  is 
  only 
  approximately 
  de- 
  

   termined 
  by 
  the 
  careful 
  piecing 
  together 
  of 
  the 
  disjointed 
  frag- 
  

   ments 
  of 
  the 
  sequence 
  found 
  in 
  several 
  scattered 
  localities. 
  Never- 
  

   theless 
  I 
  trust 
  that 
  I 
  have 
  shown 
  that, 
  even 
  from 
  the 
  physical 
  

   point 
  of 
  view, 
  a 
  sufficiency 
  of 
  evidence 
  is 
  at 
  our 
  command 
  to 
  make 
  

   it 
  clear 
  that 
  the 
  order 
  of 
  succession 
  here 
  adopted 
  is 
  in 
  all 
  proba- 
  

   bility 
  generally 
  identical 
  with 
  that 
  which 
  obtained 
  among 
  these 
  beds 
  

   previous 
  to 
  their 
  disruption. 
  

  

  The 
  irregularly 
  scattered 
  distribution 
  of 
  the 
  rocks 
  of 
  this 
  division 
  

   makes 
  it 
  difficult 
  to 
  suggest 
  a 
  collective 
  title 
  for 
  the 
  whole 
  group 
  

   that 
  shall 
  be 
  sufficiently 
  comprehensive, 
  and 
  at 
  the 
  same 
  time 
  of 
  

   definite 
  local 
  value. 
  In 
  the 
  northern 
  inlier 
  in 
  the 
  neighbourhood 
  of 
  

   the 
  farm 
  of 
  Newlands, 
  the 
  lower 
  half 
  only 
  of 
  the 
  group 
  is 
  exposed. 
  

   The 
  basal 
  beds, 
  again, 
  are 
  wholly 
  missing 
  from 
  the 
  South 
  Girvan 
  

   plateau. 
  But 
  the 
  relation 
  of 
  the 
  group 
  as 
  a 
  whole 
  to 
  the 
  underlying 
  

   formations 
  is 
  best 
  displayed 
  in 
  the 
  Newlands 
  area, 
  within 
  which 
  

   are 
  also 
  developed 
  all 
  the 
  different 
  lithological 
  varieties 
  of 
  its 
  strata, 
  

   together 
  with 
  several 
  distinct 
  groups 
  of 
  its 
  fossils. 
  Hence 
  it 
  will 
  be 
  

   most 
  convenient 
  to 
  distinguish 
  it 
  by 
  the 
  title 
  of 
  the 
  Neivlands 
  Series. 
  

  

  The 
  strata 
  of 
  this 
  Newlands 
  Series 
  consist 
  of 
  massive 
  beds 
  of 
  

   shelly 
  sandstones 
  or 
  barren 
  gritstones, 
  occasionally 
  passing 
  into 
  

   coarse 
  conglomerates 
  and 
  boulder-beds, 
  and 
  alternating 
  with 
  thick 
  

   zones 
  of 
  grey, 
  green, 
  and 
  black 
  Graptolitic 
  shales. 
  

  

  A 
  striking 
  peculiarity 
  of 
  the 
  coarse 
  beds 
  of 
  this 
  group 
  is 
  their 
  

   property 
  of 
  weathering 
  to 
  a 
  buff 
  or 
  yellow 
  colour 
  under 
  the 
  action 
  

   of 
  the 
  weather. 
  In 
  the 
  matter 
  of 
  fossils 
  this 
  group 
  is 
  altogether 
  

   the 
  most 
  prolific 
  in 
  the 
  Girvan 
  succession. 
  

  

  The 
  order 
  of 
  sequence 
  of 
  the 
  Newlands 
  Series 
  is 
  given 
  in 
  the 
  

   following 
  scheme, 
  in 
  ascending 
  order 
  : 
  — 
  

  

  Q. 
  J.G.S. 
  No. 
  152. 
  2x 
  

  

  