﻿ANNIVERSARY 
  ADDEESS 
  OF 
  THE 
  PRESIDENT. 
  205 
  

  

  feature 
  in 
  Yorkshire, 
  yet 
  palaeontologically 
  it 
  is 
  of 
  much 
  importance. 
  

   Leckenby, 
  Lycett, 
  Hudleston, 
  and 
  others 
  have 
  written 
  its 
  history 
  

   through 
  the 
  fossils 
  collected. 
  It 
  physically 
  marks 
  the 
  termination 
  

   of 
  the 
  Upper 
  Estuarine 
  series 
  of 
  the 
  Lower 
  Oolite, 
  constituting, 
  

   with 
  the 
  Dogger, 
  Grey 
  Limestone, 
  and 
  Millepore-bed, 
  four 
  marine 
  

   episodes 
  in 
  the 
  greatly 
  developed 
  Estuarine 
  group 
  of 
  Yorkshire. 
  

   7 
  genera 
  and 
  7 
  species 
  also 
  pass 
  to 
  the 
  Oxford 
  Clay, 
  many 
  species, 
  

   however, 
  avoiding 
  this 
  argillaceous 
  deposit, 
  and 
  reappearing 
  in 
  the 
  

   higher 
  Corallian 
  beds, 
  where 
  9 
  genera 
  and 
  17 
  species 
  have 
  been 
  

   observed. 
  

  

  Gasteropoda. 
  — 
  20 
  genera 
  and 
  only 
  28 
  species 
  have 
  as 
  yet 
  been 
  

   described 
  from 
  the 
  Cornbrash. 
  14 
  of 
  the 
  20 
  genera 
  are 
  represented 
  

   only 
  by 
  1 
  species 
  each, 
  4 
  by 
  2 
  species, 
  and 
  the 
  remaining 
  2 
  by 
  3 
  

   species 
  each. 
  We 
  might 
  almost 
  say 
  that 
  here 
  specific 
  representation 
  

   has 
  no 
  value. 
  5 
  genera 
  and 
  6 
  species 
  pass 
  to 
  the 
  Kellaways 
  Rock, 
  

   3 
  genera 
  and 
  3 
  species 
  to 
  the 
  Oxford 
  Clay, 
  and 
  4 
  genera 
  and 
  4 
  species 
  

   to 
  the 
  Corallian 
  beds. 
  9 
  genera 
  and 
  11 
  species 
  are 
  entirely 
  confined 
  

   to 
  the 
  Cornbrash. 
  It 
  is 
  essential 
  that 
  I 
  should 
  name 
  these 
  11 
  species 
  ; 
  

   they 
  have 
  value 
  now, 
  but 
  in 
  time 
  may 
  not. 
  They 
  are 
  : 
  — 
  Actceonina 
  

   scarburgensis, 
  Amberlya 
  armigera, 
  Ceritella 
  costata, 
  Nerincea 
  granu- 
  

   lata, 
  Nerita 
  granulata, 
  Neritopsis 
  dArcliiaci, 
  N. 
  Guerrei, 
  Purpuroidea 
  

   ornata, 
  Trochus 
  strigosus, 
  Chemnitzia 
  vetusta, 
  and 
  C. 
  vittata. 
  Only 
  

   2 
  species 
  connect 
  the 
  Forest 
  Marble 
  and 
  Cornbrash, 
  viz. 
  Actceonina 
  

   marginata 
  and 
  Patella 
  cingidata. 
  6 
  species 
  pass 
  to 
  the 
  succeeding 
  

   Kellaways 
  Rock 
  in 
  Yorkshire 
  ; 
  these 
  are 
  Pleurotomaria 
  granulata, 
  

   Natica 
  (or 
  Littorina) 
  punctata, 
  Amberlya 
  ornata, 
  Dentalium 
  entaloi- 
  

   deum, 
  Alaria 
  trifida, 
  and 
  A. 
  bispinosa. 
  There 
  is 
  no 
  more 
  unsatis- 
  

   factory 
  group 
  of 
  Mollusca 
  in 
  the 
  Cornbrash 
  than 
  the 
  Gasteropoda. 
  

   There 
  are 
  few 
  species 
  and 
  few 
  individuals, 
  and 
  these 
  are 
  seldom 
  

   well 
  preserved. 
  

  

  Cephalopoda. 
  Ammonites. 
  — 
  Ammonites 
  discus, 
  A. 
  Herveyi, 
  and 
  A. 
  

   macrocephalus 
  constitute 
  the 
  Ammonitidse. 
  A. 
  macrocephalus 
  ranges 
  

   into 
  the 
  Kellaways 
  Hock 
  and 
  Oxford 
  Clay. 
  

  

  Nautili. 
  — 
  Nautilus 
  hexagonus 
  is 
  the 
  only 
  species 
  ; 
  it 
  occurs 
  also 
  in 
  

   the 
  Kellaways 
  Rock 
  and 
  Corallian 
  beds. 
  

  

  Belemnites. 
  — 
  No 
  Dibranchiata 
  known. 
  

  

  Pisces. 
  — 
  Asteracanthus 
  acuius 
  and 
  Isodius 
  leptognathus 
  constitute 
  

   all 
  the 
  fishes 
  known 
  in 
  the 
  Cornbrash. 
  

  

  Reptilia. 
  — 
  Remains 
  of 
  Megalosaurus 
  Bucklandi 
  occur, 
  and 
  this 
  is 
  

   the 
  only 
  form 
  known. 
  

  

  Mammalia. 
  — 
  None 
  known. 
  

  

  For 
  the 
  Analysis 
  of 
  the 
  Cornbrash 
  species, 
  see 
  Table 
  XXXY. 
  

   p. 
  206. 
  

  

  