﻿PEOE. 
  C. 
  LAPWOETH 
  Otf 
  THE 
  GIEVAN 
  STJCCESSIOX. 
  601 
  

  

  (2) 
  Dictyonema-zone. 
  — 
  Hard 
  flaggy 
  shales 
  (9 
  feet), 
  with 
  ribs 
  of 
  

   grey 
  calcareous 
  rocks. 
  In 
  certain 
  zones 
  these 
  beds 
  contain 
  an 
  

   abundance 
  of 
  Dictyonema, 
  together 
  with 
  numerous 
  fragments 
  of 
  

   Phyllopoda, 
  Lingulidce, 
  and 
  DiplograpticUe. 
  

  

  The 
  characteristic 
  forms 
  are 
  Dictyonema, 
  Ganocladium, 
  Lingula. 
  

  

  (3) 
  Dionide-he&s. 
  — 
  Finally 
  we 
  have 
  a 
  thickness 
  of 
  about 
  6 
  feet 
  of 
  

   mudstones, 
  containing 
  such 
  a 
  large 
  proportion 
  of 
  calcareous 
  matter 
  

   that 
  in 
  places 
  they 
  rather 
  deserve 
  the 
  title 
  of 
  impure 
  nodular 
  lime- 
  

   stones. 
  They 
  afford 
  a 
  large 
  and 
  varied 
  association 
  of 
  fossils, 
  some 
  

   of 
  which 
  are 
  beautifully 
  preserved. 
  

  

  The 
  commonest 
  collected 
  from 
  these 
  beds 
  by 
  Mrs. 
  Gray 
  or 
  myself 
  

   include 
  : 
  — 
  

  

  Trinucleus 
  seticornis, 
  His. 
  

   Asaphus, 
  sp. 
  

   Illaenus 
  Bowrnanni, 
  Salt. 
  

   Agnostus 
  perrugatus, 
  Barr. 
  

  

  Murckisonia. 
  

   Belleroplion. 
  

   Ctenodonta. 
  

   Ortkonota. 
  

  

  Before 
  terminating 
  the 
  description 
  of 
  the 
  Whitehouse-Bay 
  beds 
  at 
  

   this 
  locality, 
  mention 
  must 
  be 
  made 
  of 
  the 
  section 
  visible 
  in 
  the 
  

   lower 
  reaches 
  of 
  the 
  Byne-Hill 
  Burn, 
  which 
  empties 
  itself 
  into 
  

   AEyoch 
  Bay 
  a 
  few 
  yards 
  to 
  the 
  south-west 
  of 
  the 
  locality 
  we 
  have 
  

   last 
  noticed 
  in 
  detail. 
  These 
  beds 
  are 
  exposed 
  in 
  the 
  stream-course 
  

   near 
  its 
  mouth, 
  and 
  are 
  of 
  the 
  same 
  general 
  character 
  as 
  those 
  of 
  

   the 
  majority 
  of 
  the 
  Whitehouse 
  group, 
  to 
  which 
  they 
  unquestionably 
  

   belong 
  ; 
  but 
  the 
  absence 
  of 
  definite 
  ribs 
  of 
  flagstone 
  from 
  amoug 
  the 
  

   soft 
  blue 
  shaly 
  mudstones 
  of 
  which 
  these 
  Byne-Bum 
  beds 
  are 
  made 
  

   up, 
  will 
  not 
  allow 
  us 
  to 
  parallel 
  the 
  little 
  group 
  satisfactorily 
  with 
  

   any 
  of 
  the 
  zones 
  already 
  described. 
  In 
  the 
  Byne-Hill 
  Burn 
  they 
  

   consist 
  of 
  about 
  100 
  feet 
  of 
  soft 
  blue 
  flaggy 
  mudstones, 
  arranged 
  in 
  

   thin 
  beds, 
  and 
  striped 
  with 
  numerous 
  seams 
  of 
  carbonaceous 
  matter. 
  

  

  They 
  contain 
  some 
  well-preserved 
  Graptolites, 
  viz. 
  : 
  — 
  

  

  Leptograptus 
  flaccidus, 
  Hall. 
  

   Pleurograptus 
  linearis, 
  Carr. 
  

   Dicellograptus 
  Morrisi, 
  Hopk. 
  

  

  Diplograptus 
  quadrimucronatus, 
  Hall. 
  

  

  foliaceus, 
  His. 
  

  

  Climacograprus 
  tubuliferus, 
  Lapw. 
  

  

  The 
  Myoch-Bay 
  and 
  Byne-Hill-Burn 
  exposures 
  are 
  the 
  final 
  ex- 
  

   hibitions 
  of 
  the 
  Whitehouse 
  Beds 
  in 
  this 
  locality, 
  the 
  strike 
  of 
  the 
  

   strata 
  carrying 
  them 
  inland 
  beneath 
  the 
  cultivated 
  flats 
  of 
  Shalloch 
  

   and 
  Ballochmyle. 
  

  

  3. 
  Barren 
  Flagstones 
  of 
  Shalloch 
  Mill. 
  — 
  The 
  band 
  of 
  purple 
  and 
  

   grey 
  fossiliferous 
  mudstones 
  of 
  the 
  Whitehouse 
  Beds 
  last 
  described 
  

   is 
  succeeded 
  to 
  the 
  northward, 
  throughout 
  the 
  whole 
  extent 
  of 
  its 
  

   range 
  from 
  Whitehouse 
  to 
  Myoch 
  Bay, 
  by 
  a 
  thick 
  series 
  of 
  shales, 
  

   flagstones, 
  and 
  greywackes 
  of 
  a 
  dull 
  greyish-green 
  colour, 
  generally 
  

   destitute 
  of 
  all 
  trace 
  of 
  unequivocal 
  fossil 
  remains 
  (III., 
  fig. 
  17). 
  

   The 
  breadth 
  of 
  this 
  Barren-flagstone 
  group 
  upon 
  the 
  ground 
  at 
  its 
  

   widest 
  horizontal 
  extension 
  (as 
  near 
  Woodland 
  Point) 
  is 
  about 
  

   200 
  yards. 
  As 
  the 
  beds 
  are 
  nearly 
  perpendicular, 
  this 
  would 
  give 
  

   the 
  group 
  an 
  approximate 
  thickness 
  of 
  about 
  500 
  feet. 
  

  

  For 
  the 
  first 
  50 
  feet 
  of 
  their 
  thickness 
  the 
  Barren-flagstone 
  strata 
  

  

  . 
  J.G.S. 
  No. 
  152. 
  2 
  s 
  

  

  