﻿ANNIVERSARY 
  ADDRESS 
  OF 
  THE 
  PRESIDENT. 
  87 
  

  

  miles 
  become 
  reduced 
  from 
  75 
  feet 
  to 
  5 
  feefc. 
  This 
  " 
  attenuation- 
  

   gives 
  a 
  gradient 
  of 
  1 
  in 
  41 
  5 
  for 
  natural 
  slope 
  of 
  the 
  upper 
  surface 
  " 
  

   (Hudleston, 
  loc. 
  cit. 
  p. 
  367). 
  The 
  grand 
  section 
  and 
  precipices 
  of 
  

   the 
  Kellaways 
  Rock 
  at 
  Yewdale 
  Scar 
  in 
  Newtondale, 
  8 
  miles 
  W. 
  by 
  N". 
  

   of 
  Hackness, 
  is 
  graphically 
  described; 
  and 
  his 
  bold 
  speculations 
  as 
  to 
  

   its 
  association 
  with 
  the 
  Oxford 
  Clay 
  and 
  Coralline 
  beds 
  are 
  of 
  much 
  

   significance. 
  A 
  sectionis 
  devoted 
  to 
  the 
  fossil 
  contents 
  of 
  the 
  Kello- 
  

   way 
  rocks. 
  Mr. 
  Hudleston 
  points 
  out, 
  and 
  that 
  truly, 
  that 
  the 
  fauna 
  

   " 
  of* 
  the 
  upper 
  part 
  of 
  the 
  Kelloway 
  rock 
  of 
  Yorkshire, 
  as 
  indicated 
  

   by 
  its 
  Ammonites, 
  embraces 
  much 
  of 
  the 
  Oxfordian 
  of 
  English 
  geolo- 
  

   gists." 
  The 
  question 
  then 
  arises, 
  " 
  Are 
  the 
  fossiliferous 
  Cephalopoda- 
  

   beds 
  in 
  the 
  upper 
  part 
  of 
  the 
  Kelloway 
  rock 
  at 
  Scarborough, 
  at 
  Red 
  

   Cliff, 
  and 
  at 
  Gristhorpe 
  wholly 
  contemporaneous 
  deposits 
  ? 
  " 
  At 
  Scar- 
  

   borough, 
  species 
  of 
  the 
  group 
  Ornati 
  are 
  plentiful, 
  and 
  at 
  Gristhorpe 
  

   the 
  Cordati, 
  especially 
  Am. 
  Lamberti 
  and 
  A. 
  vertumnus 
  &c. 
  The 
  

   accompanying 
  is, 
  I 
  believe, 
  a 
  nearly 
  complete 
  generalized 
  list 
  of 
  the 
  

   fauna 
  of 
  the 
  Kellaways 
  Rock 
  of 
  Yorkshire 
  : 
  — 
  

  

  Belemnites 
  2 
  species. 
  

  

  Nautilus 
  1 
  „ 
  

  

  Ammonites 
  40 
  ,, 
  

  

  Gasteropoda. 
  . 
  11 
  genera 
  17 
  ,, 
  

  

  Monomyaria. 
  . 
  11 
  ,, 
  23 
  ,, 
  

  

  Dimyaria 
  .... 
  19 
  „ 
  44 
  „ 
  

  

  Brachiopoda. 
  . 
  4 
  „ 
  4 
  „ 
  

  

  Crustacea 
  .... 
  1 
  „ 
  1 
  ,, 
  

  

  Eish 
  1 
  ,. 
  1 
  „ 
  

  

  50 
  133 
  

  

  Nautilus 
  heooagonus 
  stands 
  alone 
  in 
  the 
  northern 
  Kellaways, 
  and 
  

   Bel. 
  Owenii 
  and 
  B. 
  hastatus 
  are, 
  individually, 
  abundant. 
  These 
  two 
  

   species 
  have 
  been 
  found 
  at 
  the 
  new 
  exposure 
  of 
  the 
  Kellaways 
  Rock 
  

   at 
  North 
  Cave, 
  where 
  I 
  found 
  Am. 
  Gowerianus 
  and 
  Am. 
  vertumnus 
  

   associated 
  with 
  them, 
  and 
  hundreds 
  of 
  Gryphcea 
  dilatata 
  and 
  Pinna 
  

   cuneata 
  lower 
  down. 
  About 
  20 
  species 
  of 
  Lamellibranchiata 
  and 
  

   5 
  Gasteropoda 
  pass 
  to 
  the 
  Oxford 
  Clay 
  ; 
  these 
  numbers 
  apply 
  to 
  the 
  

   group 
  generally, 
  and 
  for 
  all 
  British 
  localities. 
  

  

  A 
  marked 
  and 
  striking 
  feature 
  in 
  the 
  Kellaways 
  Rock 
  of 
  York- 
  

   shire 
  is 
  the 
  sudden 
  appearance 
  and 
  abundance 
  of 
  its 
  Ammonites. 
  

   Whence 
  came 
  they 
  ? 
  Bearing 
  in 
  mind 
  that 
  only 
  one 
  species 
  is 
  found 
  

   in 
  the 
  underlying 
  Cornbrash, 
  and 
  two 
  or 
  three 
  in 
  the 
  Lincolnshire 
  

   Limestone, 
  and 
  here 
  we 
  have 
  40, 
  39 
  of 
  which 
  never 
  appeared 
  

   before 
  or 
  in 
  lower 
  beds 
  in 
  Britain, 
  as 
  Mr. 
  Hudleston 
  remarks, 
  it 
  

   was 
  " 
  a 
  regular 
  invasion 
  and 
  nothing 
  less." 
  He 
  suggests 
  that 
  

   " 
  probably 
  this 
  great 
  sandbank 
  was 
  deposited 
  during 
  a 
  subsidence 
  

   of 
  this 
  region 
  far 
  more 
  continuous 
  in 
  time 
  and 
  extended 
  in 
  space 
  

   than 
  those 
  more 
  partial 
  depressions 
  which, 
  during 
  the 
  period 
  of 
  the 
  

   Lower 
  Oolites, 
  had 
  in 
  this 
  region 
  intercalated 
  the 
  spoils 
  of 
  the 
  sea 
  

   with 
  those 
  of 
  the 
  estuary 
  and 
  marsh. 
  This 
  more 
  continuous 
  descent 
  

   seems 
  at 
  length 
  to 
  have 
  removed 
  or 
  lowered 
  barriers 
  which 
  had 
  

  

  