﻿648 
  PROF. 
  C. 
  LAPWORTH 
  ON 
  THE 
  GIRVAN 
  SUCCESSION. 
  

  

  The 
  beds 
  are 
  much 
  shattered, 
  and 
  their 
  relations 
  to 
  the 
  purple 
  

   mudstones 
  of 
  the 
  succeeding 
  zone 
  to 
  the 
  southward 
  are 
  somewhat 
  

   obscure, 
  and 
  are 
  in 
  all 
  probability 
  indicative 
  of 
  the 
  presence 
  of 
  a 
  

   line 
  of 
  fault 
  at 
  the 
  point. 
  

  

  For 
  the 
  next 
  half-mile 
  the 
  beds 
  of 
  the 
  calcareous 
  Camregan 
  zone 
  

   are 
  obscured 
  by 
  drift 
  and 
  vegetation 
  : 
  but 
  a 
  few 
  yards 
  to 
  the 
  west 
  of 
  

   the 
  boundary-line 
  between 
  the 
  Killochau 
  and 
  Bargany 
  estates 
  they 
  

   are 
  exhibited 
  in 
  several 
  small 
  excavations 
  at 
  the 
  head 
  of 
  Cuddy- 
  

   stone 
  Burn. 
  These 
  hollows 
  show 
  only 
  the 
  more 
  shaly 
  beds 
  of 
  the 
  

   series, 
  but 
  these 
  are 
  abundantly 
  fossiliferous. 
  They 
  contain 
  the 
  

   usual 
  forms 
  of 
  Rhynchonella, 
  Atrypa, 
  and 
  Encrinurus, 
  frequently 
  in 
  

   an 
  excellent 
  state 
  of 
  preservation. 
  

  

  In 
  the 
  burn-course 
  below, 
  and 
  amid 
  the 
  surrounding 
  patches 
  of 
  

   heather 
  and 
  long 
  grass, 
  evidences 
  of 
  the 
  presence 
  of 
  the 
  remaining 
  

   fossiliferous 
  beds 
  of 
  the 
  Camregan 
  group 
  are 
  found 
  in 
  the 
  form 
  of 
  

   angular 
  blocks 
  of 
  yellow 
  gritstone 
  and 
  fine 
  conglomerate, 
  filled 
  with 
  

   Pentamerus 
  oblongus, 
  and 
  the 
  characteristic 
  hard 
  calcareous 
  flaggy 
  

   beds, 
  crowded 
  with 
  Petraia 
  or 
  Lindstrosmia. 
  

  

  This 
  is 
  the 
  final 
  exposure 
  of 
  strata 
  of 
  the 
  Camregan 
  band 
  in 
  this 
  

   direction, 
  for 
  a 
  few 
  yards 
  to 
  the 
  west 
  it 
  must 
  be 
  cut 
  out 
  by 
  the 
  

   great 
  Braehill 
  fault 
  ; 
  but 
  blocks 
  of 
  the 
  coralline 
  flags 
  and 
  Penta- 
  

   mmts-gritstonc 
  are 
  found 
  at 
  intervals 
  in 
  the 
  drift 
  down 
  the 
  entire 
  

   course 
  of 
  Cuddystone 
  Burn, 
  and 
  are 
  frequent 
  in 
  the 
  debris 
  collected 
  

   off 
  the 
  neighbouring 
  fields. 
  

  

  Sections 
  West 
  of 
  Penwhajpjple 
  Glen. 
  — 
  From 
  our 
  typical 
  section 
  in 
  

   Penwhapple 
  Glen 
  the 
  strata 
  of 
  the 
  Camregan 
  grits 
  mount 
  the 
  east 
  

   cliffs 
  of 
  the 
  glen, 
  and, 
  crossing 
  the 
  Tralorg 
  road, 
  are 
  shown 
  again 
  

   in 
  the 
  course 
  of 
  the 
  southern 
  arm 
  of 
  the 
  Penkill 
  Burn. 
  Here 
  only 
  

   a 
  few 
  feet 
  of 
  the 
  calcareous 
  zone 
  and 
  the 
  overlying 
  yellow 
  grits 
  are 
  

   exposed 
  ; 
  but 
  the 
  limestone 
  beds 
  are 
  so 
  convenient 
  of 
  access 
  that 
  

   they 
  have 
  been 
  long 
  and 
  successfully 
  worked 
  by 
  collectors, 
  and 
  have 
  

   afforded, 
  especially 
  to 
  the 
  extended 
  and 
  enthusiastic 
  researches 
  of 
  

   Mrs. 
  Gray, 
  a 
  large 
  suite 
  of 
  fossils 
  of 
  all 
  groups. 
  

  

  In 
  addition 
  to 
  the 
  usual 
  Pentameri. 
  Rhynchonellidse, 
  &c, 
  wo 
  

   find:— 
  

  

  Bronteus 
  Brongniarti, 
  Barr. 
  

   Cheirurus 
  trispinosus, 
  Wyv.-Th. 
  

   Encrinurus 
  variolaris, 
  Brongn. 
  

  

  Strophomena 
  applanata. 
  

  

  antiquata. 
  

  

  Phragmoceras 
  compressum. 
  

  

  and 
  a 
  host 
  of 
  other 
  well-known 
  and 
  typical 
  Silurian 
  forms. 
  Indeed 
  

   this 
  little 
  spot 
  may 
  well 
  be 
  defined 
  as 
  the 
  typical 
  fossil-bearing 
  

   exposure 
  of 
  the 
  Camregan 
  Limestone. 
  

  

  For 
  the 
  next 
  two 
  miles 
  the 
  strata 
  of 
  this 
  zone 
  are 
  hidden 
  below 
  

   the 
  grass-clad 
  surface 
  of 
  the 
  hills 
  ; 
  but 
  in 
  the 
  exact 
  continuation 
  of 
  

   the 
  line 
  of 
  strike 
  we 
  find 
  an 
  excellent 
  exposure 
  of 
  its 
  fossil-bearing 
  

   shaly 
  beds 
  in 
  a 
  branch 
  of 
  the 
  Bargany 
  Burn, 
  near 
  the 
  western 
  base 
  of 
  

   the 
  Hadyard 
  Hills. 
  At 
  this 
  spot 
  we 
  discover 
  the 
  shaly 
  strata 
  which 
  

   occur 
  at 
  the 
  junction 
  of 
  the 
  Camregan 
  Limestone 
  and 
  the 
  fossi- 
  

   liferous 
  zone 
  of 
  purple 
  mudstones. 
  

  

  The 
  grey 
  flaggy 
  shales 
  to 
  the 
  south 
  afford 
  an 
  abundance 
  of 
  casts 
  

  

  

  