﻿88 
  PROCEEDINGS 
  OF 
  THE 
  GEOLOGICAL 
  SOCIETY. 
  

  

  hitherto 
  kept 
  out 
  the 
  waters 
  of 
  a 
  sea 
  swarming 
  with 
  strange 
  Cepha- 
  

   lopoda 
  " 
  (Hudleston, 
  he. 
  cit. 
  p. 
  374). 
  I 
  estimate 
  the 
  number 
  of 
  

   genera 
  in 
  the 
  Kellaways 
  Eock 
  of 
  England 
  at 
  51, 
  and 
  the 
  species 
  at 
  

   166. 
  They 
  will 
  be 
  discussed 
  under 
  the 
  tabular 
  analysis. 
  

  

  Oxford 
  Clay. 
  — 
  This 
  is 
  grandly 
  shown 
  north 
  of 
  Filey 
  Brig, 
  at 
  

   Gristhorpe 
  and 
  Clayton 
  Bays, 
  capped 
  by 
  the 
  bold 
  cornice 
  of 
  the 
  Lower 
  

   Calc 
  Grit, 
  sweeping 
  down 
  in 
  a 
  gentle 
  curve 
  or 
  slope 
  to 
  the 
  shore 
  ; 
  

   its 
  thickness 
  generally 
  may 
  be 
  assumed 
  to 
  be 
  from 
  130 
  to 
  150 
  feet. 
  

  

  The 
  entire 
  fauna 
  is 
  a 
  poor 
  one 
  ; 
  but 
  the 
  Cephalopoda 
  and 
  Dimyaria 
  

   exceed 
  all 
  other 
  groups 
  numerically. 
  Forty-five 
  species 
  of 
  Ammo- 
  

   nites 
  are 
  known 
  in 
  Britain, 
  and 
  twelve 
  or 
  fourteen 
  species 
  in 
  York- 
  

   shire. 
  The 
  whole 
  fauna 
  for 
  England 
  and 
  Scotland, 
  including 
  the 
  

   Staffin 
  Shales 
  &c, 
  is 
  as 
  follows 
  : 
  — 
  

  

  Genera. 
  Species. 
  

  

  Plantse 
  1 
  .... 
  1 
  

  

  Protozoa 
  3 
  .... 
  3 
  

  

  Ccelenterata 
  (none). 
  

  

  Echinodermata 
  3 
  .... 
  3 
  

  

  Annelida 
  2 
  .... 
  2 
  

  

  Crustacea 
  5 
  6 
  

  

  Bryozoa 
  (none). 
  

  

  Brachiopoda 
  5 
  .... 
  10 
  

  

  Monomyaria 
  9 
  .... 
  26 
  

  

  Dimyaria 
  21 
  .... 
  48 
  

  

  Gasteropoda 
  10 
  .... 
  17 
  

  

  Ammonites 
  1 
  .... 
  45 
  

  

  Ancyloceras 
  1 
  .... 
  1 
  

  

  Nautilus 
  (none). 
  

  

  Belemnites 
  1 
  .... 
  13 
  

  

  Teuthidse 
  2 
  .... 
  2 
  

  

  Pisces 
  3 
  .... 
  4 
  

  

  Eeptilia 
  7 
  .... 
  13 
  

  

  74 
  .... 
  194 
  

  

  Subsequent 
  to 
  the 
  Lias, 
  no 
  period 
  in 
  the 
  early 
  history 
  of 
  the 
  

   Jurassic 
  seas 
  of 
  Britain 
  presents 
  us 
  with 
  such 
  an 
  assemblage 
  of 
  

   Ammonites. 
  The 
  Lias 
  yields 
  220 
  species, 
  the 
  Inferior 
  Oolite 
  42, 
  

   the 
  Great 
  Oolite 
  7, 
  the 
  Kellaways 
  Eock 
  40, 
  and 
  now 
  we 
  have 
  present 
  

   in 
  the 
  Oxford 
  Clay 
  45 
  species, 
  18 
  or 
  20 
  of 
  which 
  are 
  probably 
  

   common 
  to 
  it 
  and 
  the 
  Kellaways 
  below. 
  The 
  Oxfordian 
  stage 
  doubt- 
  

   less 
  yields 
  the 
  most 
  ornate 
  Ammonites 
  in 
  the 
  British 
  strata, 
  not 
  even 
  

   excepting 
  the 
  Gault. 
  No 
  species 
  of 
  Nautilus 
  has 
  yet 
  occurred 
  in 
  

   the 
  Oxford 
  Clay, 
  either 
  in 
  Yorkshire 
  or 
  elsewhere 
  in 
  England. 
  So 
  

   much 
  is 
  said 
  in 
  Mr. 
  Hudleston's 
  paper 
  upon 
  the 
  fauna 
  of 
  the 
  

   Oxfordian 
  stage 
  and 
  the 
  particular 
  species 
  that 
  characterize 
  the 
  two 
  

   subdivisions, 
  that 
  comment 
  on 
  my 
  part 
  is 
  needless. 
  I 
  recommend 
  

   all 
  interested 
  in 
  Jurassic 
  geology 
  to 
  master 
  the 
  details 
  therein 
  given. 
  

   There 
  is 
  much 
  to 
  be 
  done 
  with 
  regard 
  to 
  the 
  palaeontology 
  of 
  the 
  

   Oxford 
  Clay 
  and 
  the 
  range 
  or 
  vertical 
  distribution 
  of 
  its 
  organic 
  

  

  