﻿x 
  6o 
  proceedings 
  op 
  the 
  geological 
  society. 
  

  

  connected 
  (with 
  other 
  groups) 
  the 
  Lias 
  and 
  the 
  Lower 
  Oolite, 
  re- 
  

   quires 
  critical 
  examination 
  ; 
  they 
  are 
  all 
  abnormal 
  either 
  in 
  size 
  or 
  

   habit, 
  dwarfed 
  or 
  semideformed. 
  

  

  Very 
  few 
  species 
  occur 
  in 
  the 
  lowest 
  zones 
  of 
  the 
  Lower 
  Lias. 
  

   Those 
  beds, 
  characterized 
  by 
  the 
  presence 
  of 
  JEgoceras 
  planorbis, 
  

   possess 
  only 
  3 
  or 
  4 
  species, 
  Protocardium 
  Phillipsianum, 
  PUuromya 
  

   croivcombeia, 
  Unicardium 
  cardioides, 
  and 
  a 
  Cardinia 
  allied 
  to 
  C. 
  cras- 
  

   siuscula. 
  All 
  these 
  pass 
  to 
  the 
  Angulatum-beds 
  above, 
  in 
  one 
  or 
  

   other 
  of 
  the 
  areas, 
  where 
  exposed; 
  they 
  are 
  also 
  common 
  con- 
  

   tinental 
  species 
  at 
  the 
  same 
  horizon. 
  Mr. 
  E. 
  B. 
  Tawney, 
  in 
  his 
  

   paper 
  " 
  On 
  the 
  "Western 
  Limits 
  of 
  the 
  Rhaetic 
  beds 
  in 
  South 
  Wales"*, 
  

   and 
  Professor 
  Tate, 
  in 
  his 
  memoirs, 
  " 
  On 
  the 
  Fossilif 
  erous 
  Development 
  

   of 
  the 
  Zone 
  of 
  Ammonites 
  angulatus 
  in 
  Great 
  Britain 
  "t, 
  and 
  " 
  On 
  

   the 
  Lower 
  Lias 
  of 
  the 
  ^orth-east 
  of 
  Ireland," 
  discuss 
  this 
  distribution. 
  

   Mr. 
  Tawney, 
  in 
  1866, 
  was 
  the 
  first 
  to 
  notice 
  the 
  extension 
  of 
  the 
  Rhaetie 
  

   and 
  Infra-Lias 
  beds 
  in 
  their 
  most 
  westerly 
  range 
  or 
  extension 
  ; 
  for 
  

   the 
  first 
  time, 
  too, 
  the 
  white 
  Sutton-stonc 
  series 
  received 
  from 
  him 
  

   careful 
  attention. 
  We 
  were 
  then 
  made'' 
  acquainted 
  with 
  the 
  series 
  

   of 
  beds 
  at 
  the 
  Southcrndown 
  cliff, 
  at 
  the 
  base 
  of 
  which, 
  immediately 
  

   above 
  the 
  Chert 
  band, 
  Mr. 
  Tawney 
  obtained 
  Ostrea 
  multicostata 
  and 
  

   Lima 
  tuberculata, 
  the 
  former 
  a 
  Muschelkalk 
  species, 
  which, 
  with 
  

   the 
  Astroccenian 
  corals, 
  also 
  mostly 
  of 
  that 
  age, 
  gave 
  rise 
  to 
  the 
  

   hope 
  that 
  we 
  may 
  have 
  in 
  that 
  area 
  some 
  direct 
  representative 
  of 
  the 
  

   missing 
  member 
  of 
  the 
  Trias 
  in 
  Britain. 
  Two 
  Ammonites 
  were 
  de- 
  

   tected 
  by 
  Mr. 
  Tawney 
  in 
  the 
  Sutton-stonc 
  series. 
  From 
  these 
  white 
  

   beds 
  he 
  obtained 
  33 
  species 
  ; 
  from 
  the 
  succeeding 
  Southerndown 
  

   beds 
  12 
  ; 
  and 
  from 
  the 
  Avicida-contorta 
  beds 
  25 
  species. 
  The 
  Avi- 
  

   cvla-contorta 
  series, 
  noticed 
  so 
  far 
  west 
  in 
  England 
  for 
  the 
  first 
  time, 
  

   numbered 
  25 
  species 
  ; 
  7 
  genera 
  of 
  Monomyaria, 
  and 
  4 
  genera 
  of 
  

   Dimyarian 
  Mollusca, 
  with 
  21 
  species, 
  occur 
  in 
  the 
  Sutton 
  Stone. 
  

   Professor 
  Tate 
  in 
  1863 
  described 
  the 
  Rhaetie 
  and 
  Liassic 
  strata 
  near 
  

   Belfast 
  : 
  from 
  the 
  latter 
  ho 
  obtained 
  55 
  species, 
  13 
  amongst 
  them 
  

   being 
  Monomyarian 
  bivalves 
  and 
  16 
  Dimyarian. 
  

  

  In 
  1867, 
  in 
  his 
  paper 
  published 
  in 
  the 
  Journal 
  of 
  our 
  Society 
  

   upon 
  the 
  Lower 
  Lias 
  of 
  the 
  N.E. 
  of 
  Ireland, 
  Mr. 
  Tate 
  regarded 
  the 
  

   Lower 
  Lias 
  of 
  Ireland 
  as 
  capable 
  of 
  being 
  divided 
  into 
  4 
  members 
  or 
  

   series, 
  namely: 
  — 
  

  

  1, 
  the 
  zone 
  of 
  JEgoceras 
  planorbis 
  ; 
  2, 
  the 
  zone 
  of 
  JEgoceras 
  angu- 
  

   latum; 
  3, 
  the 
  zone 
  of 
  Arietites 
  Bucldandi; 
  and 
  4, 
  beds 
  superior 
  to 
  

   those 
  with 
  A. 
  Bucldandi, 
  which 
  he 
  termed 
  the 
  Belemnites-acutus 
  zone, 
  

   the 
  equivalent 
  of 
  the 
  " 
  Belemnitic 
  beds 
  " 
  of 
  the 
  Lower 
  Lias 
  of 
  

   France, 
  Germany, 
  and 
  England 
  (Lyme 
  Regis), 
  and 
  the 
  highest 
  

   beds 
  of 
  the 
  Lias 
  known 
  in 
  Ireland. 
  The 
  singular 
  " 
  Portrush 
  " 
  

   beds 
  Mr. 
  Tate 
  unhesitatingly 
  referred 
  to 
  the 
  zone 
  of 
  JZgoceras 
  pla- 
  

   norbis 
  ; 
  only 
  5 
  species 
  of 
  Dimyaria 
  occur 
  therein, 
  the 
  remaining 
  8 
  

   being 
  Monomyaria 
  ; 
  only 
  5 
  species 
  of 
  the 
  whole 
  18 
  are 
  re- 
  

   stricted 
  to 
  the 
  zone. 
  The 
  succeeding 
  beds 
  belong 
  to 
  the 
  zone 
  of 
  

  

  * 
  Quart. 
  Journ. 
  Geol. 
  Soc. 
  vol. 
  xxii. 
  (1866). 
  

   t 
  lb. 
  vol. 
  xxiii. 
  (1867). 
  

  

  