﻿Vol. 
  53.] 
  THE 
  CRF.TACEOTJS 
  STRATA 
  OF 
  COUNT 
  1' 
  ANTRIM. 
  543 
  

  

  into 
  three 
  subdivisions 
  : 
  (1) 
  the 
  Upper 
  Chalk, 
  (2) 
  the 
  Lower 
  Chalk, 
  

   (3) 
  the 
  Arenaceous 
  or 
  Glauconous 
  or 
  Greensand 
  ; 
  but 
  under 
  these 
  

   names 
  are 
  included 
  beds, 
  mainly 
  of 
  Senonian 
  age, 
  which 
  differ 
  

   chiefly 
  in 
  their 
  lithological 
  characters. 
  The 
  officers 
  of 
  the 
  Irish 
  

   Geological 
  Survey 
  have 
  recorded 
  these 
  from 
  many 
  localities, 
  as 
  

   at 
  Slieve 
  Gallion, 
  in 
  county 
  Deny, 
  and 
  at 
  Murlough 
  Bay, 
  near 
  

   Bally 
  castle. 
  

  

  In 
  the 
  Irish 
  Survey 
  Memoirs 
  7 
  & 
  8, 
  by 
  Symes, 
  Egan, 
  & 
  

   McHenry 
  ; 
  12, 
  bv 
  Nolan 
  & 
  Egan 
  ; 
  14, 
  by 
  Symes 
  & 
  McHenry 
  ; 
  18, 
  

   by 
  Nolan 
  & 
  Egan 
  ; 
  20, 
  by 
  Symes 
  ; 
  21, 
  28, 
  & 
  29, 
  by 
  Prof. 
  E. 
  Hull 
  ; 
  

   27, 
  by 
  Egan 
  ; 
  and 
  36, 
  by 
  Hull, 
  Warren, 
  & 
  Leonard, 
  the 
  litho- 
  

   logical 
  characters 
  of 
  the 
  rocks 
  are 
  discussed 
  and 
  the 
  nature 
  of 
  their 
  

   distribution 
  considered 
  in 
  some 
  detail, 
  but 
  otherwise 
  no 
  important 
  

   information 
  is 
  added 
  to 
  that 
  given 
  in 
  the 
  previously 
  quoted 
  works. 
  

  

  In 
  the 
  Proceedings 
  of 
  the 
  Belfast 
  Naturalists' 
  Eield 
  Club, 
  

   1876-77, 
  pp. 
  251-262, 
  Mr. 
  "W. 
  Gault, 
  a 
  local 
  collector, 
  expressed 
  

   his 
  views 
  on 
  the 
  Cretaceous 
  beds 
  of 
  the 
  district 
  south 
  of 
  Belfast. 
  

   This 
  paper, 
  while 
  arriving 
  at 
  conclusions 
  with 
  which, 
  on 
  many 
  

   points, 
  the 
  present 
  writer 
  finds 
  himself 
  in 
  accordance, 
  cannot 
  be 
  

   trusted 
  always, 
  so 
  far 
  as 
  the 
  identification 
  of 
  fossils 
  is 
  concerned. 
  The 
  

   association 
  of 
  Belemnitella 
  mucronata, 
  Actinocamacc 
  [Belemnitella] 
  

   ■plenus, 
  Ammonites 
  [Acanthoceras] 
  rotomagensis, 
  and 
  Micraster 
  spp., 
  

   in 
  the 
  same 
  beds 
  may 
  be 
  cited 
  as 
  an 
  example 
  of 
  the 
  need 
  of 
  caution 
  

   in 
  considering 
  the 
  bearings 
  of 
  the 
  paper. 
  The 
  most 
  important 
  

   points 
  raised 
  in 
  it 
  are 
  the 
  recognition 
  — 
  firstly, 
  of 
  the 
  zone 
  of 
  

   Exogyra 
  columba 
  as 
  being 
  of 
  Upper 
  Greensand 
  age, 
  and, 
  secondly, 
  

   of 
  the 
  existence 
  of 
  an 
  unconformity 
  between 
  the 
  above 
  and 
  the 
  

   Inoceramus 
  Grispi 
  '-zone. 
  

  

  The 
  present 
  state 
  of 
  our 
  knowledge 
  may 
  be 
  summarized 
  in 
  

   tabular 
  form, 
  as 
  shown 
  on 
  p. 
  544. 
  

  

  In 
  the 
  first 
  part 
  of 
  the 
  present 
  paper 
  a 
  detailed 
  description 
  will 
  

   be 
  given 
  of 
  the 
  principal 
  exposures 
  of 
  the 
  Cretaceous 
  in 
  County 
  

   Antrim, 
  most 
  of 
  which 
  have 
  been 
  personally 
  inspected. 
  Much 
  

   obscurity 
  has 
  undoubtedly 
  arisen, 
  owing 
  to 
  the 
  fact 
  that 
  previous 
  

   writers 
  have 
  laid 
  but 
  little 
  stress 
  on 
  the 
  local 
  variations 
  which 
  form 
  

   a 
  marked 
  feature 
  in 
  connexion 
  with 
  these 
  strata. 
  

  

  It 
  appears 
  to 
  me 
  that 
  five 
  divisions, 
  in 
  each 
  of 
  which 
  the 
  Cretaceous 
  

   rocks 
  exhibit 
  peculiar 
  characters, 
  are 
  clearly 
  marked 
  out, 
  and 
  these 
  

   will 
  be 
  considered 
  in 
  turo. 
  They 
  are 
  : 
  — 
  

  

  1. 
  A 
  Southern 
  Division, 
  extending 
  from 
  Magheralin, 
  16 
  miles 
  

   south 
  of 
  Belfast, 
  to 
  the 
  north 
  of 
  Lisburn. 
  

  

  2. 
  A 
  Central 
  Division, 
  continuing 
  the 
  above 
  from 
  Colin 
  Moun- 
  

   tain, 
  5 
  miles 
  south 
  of 
  Belfast, 
  to 
  a 
  little 
  north 
  of 
  that 
  city. 
  

  

  3. 
  An 
  Eastern 
  Division, 
  including 
  Islandmagee 
  and 
  all 
  the 
  

   exposures 
  from 
  Larne 
  to 
  Cushendall. 
  Woodburn 
  Glen, 
  near 
  Carrick- 
  

   fergus, 
  occupies 
  an 
  intermediate 
  position 
  between 
  this 
  and 
  the 
  

   previous 
  division. 
  

  

  4. 
  North 
  of 
  Cushendall, 
  and 
  passing 
  westward 
  into 
  Derry, 
  is 
  

   a 
  great 
  series 
  of 
  ancient 
  rocks, 
  from 
  pre-Devonian 
  to 
  Trias, 
  which 
  

  

  