﻿294 
  PiJOCICEDINGS 
  OF 
  THK 
  MALACOLOGICAL 
  SOCIETY. 
  

  

  by 
  John 
  Phillips^ 
  during: 
  1829 
  for 
  a 
  series 
  of 
  beds 
  on 
  the 
  Yorkshire 
  

   coast 
  ranging 
  from 
  the 
  Kinieridge 
  Chay 
  to 
  tlie 
  Gault. 
  In 
  descending 
  

   order 
  Professor 
  Jiidd 
  identified 
  as 
  Neocomian 
  the 
  following 
  beds 
  in 
  

   the 
  Speeton 
  Cliff, 
  a 
  result 
  inainly 
  arrived 
  at 
  from 
  a 
  study 
  of 
  the 
  

   Ammonites, 
  although 
  other 
  mollusciin 
  species 
  were 
  adopted 
  in 
  addition 
  

   for 
  disci'iminating 
  his 
  zonal 
  subdivisions 
  ; 
  — 
  

  

  Age 
  of 
  Deposits. 
  Characteristic 
  Mollusca. 
  

  

  Upper 
  Neocomian 
  Cephalopoda 
  : 
  Belemnites 
  semicanaliculatus, 
  

   (clays 
  and 
  cement 
  Ammonites 
  Deshayesi, 
  Ancylocerasi^}) 
  grandis. 
  

  

  beds; 
  150 
  feet). 
  Pelecypoda: 
  Ferna 
  Mullet 
  i 
  ; 
  JExogyra 
  

  

  xinuata 
  ; 
  Pecten 
  elongata, 
  orbicularis 
  ; 
  Thetis 
  

   Soiverbyi; 
  Panopcaa 
  plicata, 
  neocomiensis. 
  

   Middle 
  Neocomian 
  Cephalopoda: 
  Belemnites 
  jaculum 
  ; 
  Ammonites; 
  

   (including 
  zone 
  of 
  Ancyloceras 
  J)uvali, 
  Emerici. 
  Pelecypoda 
  : 
  

  

  Pecten 
  cinctus 
  and 
  Pecten 
  cinctns, 
  Exogyra 
  sinuata. 
  

  

  Ancyloceras 
  beds; 
  

   150 
  feet). 
  

   Loaver 
  NEocoMiAisr 
  Cephalopoda 
  : 
  Ammonites 
  Speetonensis, 
  rotula, 
  

   (containing 
  zones 
  of 
  nis^ls, 
  noricus, 
  inargt7iatus, 
  astierianus, 
  multi- 
  

  

  Ammonites 
  Speeton- 
  plicatus, 
  hystrix 
  ; 
  Belemnites 
  jaculum, 
  

  

  oisis, 
  A. 
  noricus, 
  and 
  lateralis; 
  Ancyloceras 
  Puzosianum, 
  Buvali, 
  

  

  A. 
  astierianus 
  \ 
  Emerici. 
  Gastropoda: 
  Cerithium 
  sj:)., 
  

  

  200 
  feet). 
  Trochus 
  sp. 
  Pelecypoda: 
  Exogyra 
  suh- 
  

  

  sinuata, 
  suh'plicata 
  ; 
  Thracia 
  Phillips 
  i 
  ; 
  

   Pholadomya 
  sp. 
  ; 
  Pholas 
  constricta. 
  

   Then 
  follow 
  the 
  Jurassic 
  beds 
  of 
  Portlandian, 
  Kiraeridgian, 
  etc. 
  

  

  In 
  a 
  subsequent 
  paper 
  Professor 
  Judd- 
  showed 
  that 
  the 
  Speeton 
  

   Cliff 
  beds 
  furnished 
  a 
  key 
  to 
  the 
  interpretation 
  of 
  many 
  isolated 
  

   deposits 
  of 
  similar 
  age 
  distributed 
  over 
  various 
  districts 
  of 
  J^orthem 
  

   Europe. 
  On 
  that 
  occasion 
  he 
  introduced 
  Orbigny's 
  stratigraphical 
  

   terms, 
  and 
  bracketed 
  Aptien 
  with 
  his 
  Upper 
  Neocomian, 
  Urgonien 
  

   with 
  Middle 
  IS^eoeomiau, 
  and 
  Neocomien 
  with 
  Lower 
  ISTeocomian. 
  

  

  Twenty 
  years 
  later 
  Mr. 
  Lamplugh's 
  ^ 
  investigations 
  "On 
  the 
  Sub- 
  

   divisions 
  of 
  the 
  Speeton 
  Clay 
  " 
  were 
  published, 
  the 
  Belemnites 
  forming 
  

   the 
  basis 
  of 
  classification. 
  The 
  term 
  'Middle 
  Neocomian' 
  used 
  by 
  

   Judd 
  was 
  thought 
  to 
  be 
  unnecessary, 
  since 
  the 
  beds 
  which 
  had 
  

   received 
  that 
  name 
  exhibited 
  a 
  ' 
  Lower 
  Neocomian 
  ' 
  fauna, 
  both 
  

   above 
  and 
  below. 
  Judd's 
  zone 
  of 
  Ammonites 
  astierianus 
  was 
  abolished 
  

   in 
  favour 
  of 
  the 
  zone 
  of 
  Belemnites 
  lateralis, 
  w^hich 
  comprised 
  a 
  fauna 
  

   showing 
  marked 
  Jurassic 
  affinities, 
  and 
  comparable 
  with 
  that 
  of 
  the 
  

   ' 
  Upper 
  Yolga 
  ' 
  Beds 
  of 
  Southern 
  Kussia, 
  as 
  described 
  by 
  Professors 
  

   Pavlov* 
  and 
  JSTikitin.^ 
  Lamplugh 
  therefore 
  regarded 
  the 
  zone 
  of 
  

  

  ' 
  Geology 
  of 
  Yorkshire, 
  1829, 
  p. 
  76. 
  

  

  ^ 
  Quart. 
  Journ. 
  Geol. 
  Soc, 
  vol. 
  xxvi, 
  p. 
  326, 
  1870. 
  

  

  - 
  Ibid., 
  vol. 
  xlv, 
  p. 
  575, 
  1889. 
  

  

  ^ 
  " 
  Jurassique 
  superieur 
  et 
  Cretace 
  inferieur 
  de 
  la 
  Russie 
  et 
  de 
  I'Angleterre," 
  

  

  1889. 
  

   " 
  Quelques 
  excursions 
  dans 
  les 
  Muses 
  et 
  dans 
  les 
  terrains 
  Mesozoiques 
  de 
  

  

  I'Europe 
  occidentale, 
  et 
  comparaison 
  de 
  leur 
  faune 
  avec 
  celle 
  de 
  la 
  Kussie 
  " 
  : 
  

  

  Bull. 
  Soc. 
  Beige 
  Geol., 
  vol. 
  iii, 
  pp. 
  29-58, 
  1889. 
  

  

  