﻿2IO 
  PROCEEDINGS 
  CF 
  THE 
  GEOLOGICAL 
  SOCIETY. 
  

  

  Clay. 
  I 
  believe 
  there 
  are 
  no 
  other 
  known 
  species 
  in 
  the 
  Middle 
  

   Jurassic 
  strata 
  ; 
  but 
  7 
  genera 
  and 
  13 
  species 
  occur 
  in 
  the 
  Kimme- 
  

   ridge 
  Clay. 
  

  

  Ccrlenterata. 
  — 
  None 
  known. 
  

  

  Echinodermata. 
  — 
  Pentacrinus 
  Fisher 
  i, 
  Amphiura 
  Prattii, 
  and 
  

   Cidaris 
  inspirata 
  compose 
  the 
  Echinodermal 
  fauna 
  of 
  the 
  Oxford 
  

   Clay. 
  The 
  calcareous 
  strata 
  of 
  the 
  Corallian 
  rocks 
  above 
  hold 
  a 
  

   numerous 
  series 
  (J|). 
  The 
  four 
  chief 
  horizons 
  are, 
  as 
  we 
  should 
  

   expect 
  from 
  the 
  nature 
  of 
  the 
  deposits, 
  the 
  Inferior 
  Oolite 
  (51), 
  the 
  

   Great 
  Oolite 
  (53), 
  the 
  Cornbrash 
  (23), 
  and 
  the 
  Corallian 
  beds 
  (28). 
  

   The 
  large 
  fauna 
  which 
  accompanies 
  each 
  is 
  largely 
  due 
  to 
  physical 
  

   conditions 
  and 
  adaptation. 
  The 
  above 
  3 
  species 
  are 
  confined 
  to 
  the 
  

   Oxford 
  Clay. 
  

  

  Annelida. 
  — 
  Serpula 
  intestinalis 
  and 
  S. 
  vertebralis 
  are 
  the 
  only 
  

   species 
  occurring. 
  The 
  Corallian 
  beds 
  above 
  possess 
  3 
  genera 
  and 
  

   3, 
  species. 
  

  

  Crustacea. 
  — 
  5 
  genera 
  and 
  6 
  species 
  known 
  ; 
  3 
  of 
  these 
  are 
  un- 
  

   satisfactory 
  forms 
  — 
  Estheria 
  Murchisonio?, 
  Pollicipes 
  plamdatus, 
  and 
  

   P. 
  concinnus. 
  The 
  Macrura, 
  through 
  Glyphea 
  leptomana, 
  G. 
  Strick- 
  

   landi, 
  and 
  Mecochirus 
  Pearcei, 
  constitute 
  the 
  Crustacean 
  fauna 
  of 
  

   the 
  Oxford 
  Clay. 
  None 
  pass 
  to 
  the 
  Corallian 
  rocks 
  ; 
  but 
  2 
  species 
  

   are 
  also 
  Kimmcridgian. 
  

  

  Bryozoa. 
  — 
  None 
  known. 
  

  

  Brachiopoda. 
  — 
  5 
  genera 
  and 
  10 
  species 
  range 
  through 
  the 
  Oxford 
  

   Clay, 
  viz. 
  Waldheimia 
  bucculenta, 
  W. 
  impressa 
  and 
  W. 
  ornithocephala, 
  

   Terebratula 
  insignis 
  and 
  T. 
  oxoniensis, 
  Rhynchonella 
  lacunosa 
  and 
  

   R. 
  socialis, 
  Lingula 
  Crance 
  and 
  L. 
  ovalis, 
  and 
  Discina 
  latissima 
  (?). 
  

   The 
  only 
  species 
  that 
  range 
  to 
  higher 
  beds 
  are 
  Lingula 
  ovalis 
  to 
  the 
  

   Kimmeridge 
  Clay 
  ; 
  and 
  Rhynchonella 
  lacunosa, 
  Waldheimia 
  buccu- 
  

   lenta, 
  and 
  Terebratula 
  insignis 
  to 
  the 
  Corallian 
  beds. 
  

  

  Lamellibranchiata. 
  Monomyaria. 
  — 
  With 
  the 
  7 
  genera 
  and 
  16 
  

   species 
  which 
  appeared 
  in 
  the 
  Kellaways, 
  the 
  Oxford 
  Clay 
  yields 
  

   9 
  genera 
  and 
  26 
  species, 
  only 
  7 
  of 
  which 
  are 
  restricted 
  ; 
  these 
  are 
  

   Pecten 
  lavis, 
  Ostrea 
  hebridica, 
  0. 
  incequalis, 
  Lima 
  argillacea, 
  Gryphma 
  

   elongata, 
  Avicula 
  pterosphamia, 
  and 
  Anomia 
  estuarina. 
  13 
  species 
  

   pass 
  to 
  the 
  Corallian 
  rocks 
  and 
  6 
  to 
  the 
  Kimmeridge 
  Clay. 
  The 
  species 
  

   common 
  to 
  the 
  Oxford 
  and 
  Kimmeridge 
  Clay 
  are 
  Avicula 
  dorsettensis, 
  

   Av. 
  incequalis, 
  Gervillia 
  aviculoides, 
  Pecten 
  arenatus, 
  P. 
  demissus, 
  

   and 
  P. 
  vimineus. 
  Pecten 
  is 
  the 
  only 
  genus 
  in 
  which 
  the 
  species 
  

   number 
  more 
  than 
  4. 
  

  

  Dimyaria. 
  — 
  21 
  genera 
  and 
  48 
  species 
  constitute 
  the 
  whole 
  

   fauna 
  of 
  this 
  group 
  of 
  the 
  Bivalvia 
  ; 
  8 
  genera 
  and 
  13 
  species 
  ally 
  

   the 
  Oxford 
  and 
  Kellaways 
  Dimyaria 
  ; 
  26 
  of 
  the 
  48 
  species 
  exclu- 
  

   sively 
  belong 
  to 
  the 
  Oxford 
  Clay. 
  None 
  of 
  the 
  genera 
  are 
  largely 
  

   represented; 
  10 
  genera 
  contain 
  only 
  1 
  species 
  each. 
  Cyrena, 
  

   through 
  the 
  estuarine 
  " 
  Staffin 
  shales," 
  occurs 
  for 
  the 
  first 
  time 
  in 
  

   the 
  Jurassic 
  series, 
  and 
  with 
  6 
  species. 
  In 
  the 
  Wealden 
  this 
  is 
  

   the 
  most 
  prominent 
  genus 
  amongst 
  the 
  Lamellibranchiata, 
  no 
  less 
  

   than 
  8 
  species 
  being 
  known 
  in 
  the 
  "Weald 
  Clay. 
  Trigonia 
  is 
  the 
  

  

  