﻿Yol. 
  53.] 
  THE 
  CRETACEOUS 
  STRATA 
  OF 
  COUNTY 
  ANTRIM. 
  

  

  585 
  

  

  III. 
  Conclusions 
  as 
  to 
  the 
  Sequence 
  and 
  Correlation 
  of 
  the 
  

   Irish 
  Cretaceous 
  Strata. 
  

  

  "We 
  are 
  now 
  in 
  a 
  position 
  to 
  trace 
  the 
  probable 
  secpence 
  of 
  events 
  

   in 
  Ireland, 
  comparing 
  it 
  with 
  the 
  established 
  standards 
  of 
  the 
  

   English 
  Cretaceous 
  zones, 
  and 
  in 
  doing 
  so 
  it 
  will 
  be 
  well 
  to 
  commence 
  

   with 
  the 
  lowest 
  division, 
  the 
  Glauconitic 
  Sands. 
  

  

  Glauconitic 
  Sands 
  (Zone 
  of 
  Exogyra 
  conica). 
  

  

  These 
  beds, 
  easily 
  recognized 
  by 
  their 
  deep-green 
  colour, 
  are 
  

   mainly 
  restricted 
  to 
  the 
  Eastern 
  and 
  Central 
  Divisions, 
  extending 
  

   from 
  Larne 
  to 
  Colin 
  Mountain, 
  a 
  little 
  south 
  of 
  Colin 
  Glen, 
  a 
  range 
  

   of 
  over 
  25 
  miles, 
  though 
  Portlock's 
  record 
  of 
  their 
  occurrence 
  in 
  

   Tircreven 
  Burn 
  shows 
  them 
  to 
  have 
  been 
  also 
  present 
  in 
  the 
  

   Northern 
  Division. 
  In 
  their 
  southernmost 
  exposure 
  at 
  Colin 
  

   Mountain 
  they 
  attain 
  their 
  maximum 
  thickness 
  of 
  16 
  feet, 
  in 
  all 
  

   other 
  localities 
  where 
  they 
  have 
  been 
  examined 
  varying 
  from 
  5 
  to 
  

   8 
  feet 
  thick. 
  These 
  strata 
  are 
  remarkable 
  for 
  the 
  uniformity 
  of 
  

   their 
  lithological 
  character, 
  being 
  largely 
  composed 
  of 
  glauconitic 
  

   (with 
  an 
  admixture 
  of 
  arenaceous) 
  grains, 
  and 
  containing 
  an 
  abun- 
  

   dant 
  fauna, 
  especially 
  in 
  a 
  central 
  band. 
  Exogyra 
  laevigata, 
  Sow., 
  

   is 
  ubiquitous, 
  being 
  generally 
  accompanied 
  by 
  Pecten 
  [Amussiwni] 
  

   orbicularis 
  (Mant.), 
  and 
  P. 
  \_JanircC] 
  quinquecostatus, 
  Sow. 
  

  

  In 
  addition 
  to 
  the 
  three 
  species 
  just 
  enumerated, 
  which 
  are 
  

   common 
  to 
  both 
  divisions, 
  the 
  following 
  list 
  shows 
  the 
  principal 
  

   fossils 
  obtained 
  in 
  the 
  green 
  sands 
  and 
  their 
  divisional 
  distribution 
  : 
  — 
  

  

  Class. 
  

  

  Centeal 
  Division. 
  

  

  Eastern 
  Division. 
  

  

  Reptilla 
  

  

  Vertebrae 
  of 
  Plesiosaurus. 
  

  

  Corax 
  falcatus, 
  Ag., 
  Lamna 
  

   appendiculata 
  (Ag.). 
  

  

  Lamna 
  appendiculata 
  (Ag.). 
  

  

  Pisces 
  

  

  

  Cephalopoda 
  ... 
  

  

  Ammonites 
  [Hojplites] 
  catil- 
  

  

  Ammonites 
  [Sc7dcenbachia~] 
  

  

  

  lus, 
  Sow. 
  (probably). 
  

  

  varians, 
  Sow., 
  sp. 
  (Tate). 
  

  

  

  Belemnites 
  ultimus, 
  d'Orb. 
  

  

  Belemnite 
  foreshadowing 
  Be- 
  

   lemnitella 
  \_Actinocamax] 
  

   vera 
  (Mil.). 
  

  

  Gasteropoda 
  ... 
  

  

  ? 
  Littorina 
  (numerous). 
  

  

  ? 
  Littorina. 
  

  

  Pelecypoda: 
  

  

  

  

  Dimyaria 
  

  

  Trigonia, 
  sp. 
  (mainly 
  Colin 
  

   Glen). 
  

  

  Avicula, 
  near 
  A. 
  lineata, 
  

  

  

  Romer. 
  

  

  

  Area 
  [Cucullcea] 
  carinata, 
  

  

  

  

  Sow. 
  Large 
  casts 
  of 
  Cucul- 
  

  

  

  

  lcea 
  ligeriensis 
  (d'Orb.) 
  at 
  

  

  

  

  Squires 
  Hill. 
  

  

  

  

  Casts 
  of 
  Thetis 
  Sowerbyi 
  (?), 
  

  

  

  

  Rom. 
  (large 
  at 
  Cave 
  Hill). 
  

  

  

  

  Avicula, 
  sp. 
  

  

  

  Monomyaria 
  . 
  . 
  

  

  As 
  above. 
  

  

  As 
  above, 
  and 
  Pecten 
  

   [Chlamys] 
  G-alliennei, 
  P. 
  

   \Chl.~\ 
  asper, 
  Lam. 
  

  

  

  

  Beachiopoda 
  ... 
  

  

  

  Bhynchonella 
  near 
  Bh. 
  Cuvi- 
  

   eri, 
  Sow. 
  

  

  

  

  

  

  Terebratula 
  squamosa, 
  Mant., 
  

  

  

  

  or 
  T. 
  biplicata, 
  Sow. 
  

  

  

  

  Kingena 
  lima, 
  Defr. 
  

  

  