﻿548 
  MR. 
  T. 
  ROBERTS 
  Otf 
  THE 
  UPPER 
  

  

  In 
  Rutlandshire 
  and 
  the 
  southern 
  part 
  of 
  Lincolnshire, 
  Prof. 
  Judd 
  * 
  

   recognizes 
  the 
  following 
  zoues 
  in 
  the 
  Oxford 
  Clay 
  : 
  — 
  

  

  6. 
  Clays 
  with 
  Ammonites 
  of 
  the 
  group 
  of 
  the 
  cordati. 
  

   5. 
  Clays 
  with 
  Ammonites 
  of 
  the 
  group 
  of 
  the 
  ornati. 
  

   4. 
  Clays 
  with 
  Belemnites 
  7ia 
  status. 
  

   3. 
  Clays 
  with 
  Belemnites 
  Oivenii. 
  

   2. 
  Clays 
  with 
  Nucula. 
  

   1. 
  Kellaways 
  Rock. 
  

  

  Pive 
  of 
  these 
  zones 
  are 
  stated 
  to 
  occur 
  in 
  south-west 
  Lincoln- 
  

   shire 
  f, 
  the 
  sixth 
  (uppermost) 
  being 
  concealed 
  by 
  drift. 
  

  

  The 
  pits 
  at 
  Bardney, 
  Langworthy, 
  Bishop's 
  Xorton, 
  and 
  south 
  of 
  

   Peaseholme 
  were 
  visited 
  by 
  the 
  author, 
  but 
  the 
  Oxford 
  Clay 
  may 
  

   also 
  be 
  seen 
  in 
  several 
  other 
  localities. 
  The 
  most 
  important 
  sec- 
  

   tions 
  are 
  the 
  following 
  : 
  — 
  

  

  Immediately 
  to 
  the 
  north 
  of 
  Bardney 
  Station 
  dark 
  blue 
  clays 
  

   are 
  worked 
  for 
  brick-making. 
  These 
  clays 
  have 
  yielded 
  the 
  follow- 
  

   ing 
  fossils 
  : 
  — 
  

  

  Plesiosaurus 
  (phalanges). 
  

   Ichthyosaurus 
  (-vertebra). 
  

   Ammonites 
  cordatus, 
  Sow. 
  

  

  Eugenii, 
  Hasp. 
  

   Cerithiuni 
  muricatum, 
  Sow. 
  

  

  Pinna, 
  sp. 
  

  

  Gryphsea 
  dilatata, 
  Sow. 
  

   Serpula 
  sulcata, 
  Sow. 
  

   tricarinata, 
  Sow. 
  

  

  The 
  following 
  Ammonites 
  t, 
  now 
  in 
  the 
  Jermyn 
  Street 
  Museum, 
  

   are 
  also 
  recorded 
  § 
  from 
  this 
  locality 
  : 
  — 
  

  

  Ammonites 
  perarmatus, 
  Sow. 
  

  

  excavatus, 
  Sow. 
  

  

  biplex, 
  Sow. 
  

  

  Ammonites 
  rnacrocephalus, 
  Sow. 
  

  

  arduennensis, 
  J)' 
  Orb. 
  

  

  plicatilis, 
  Sow. 
  

  

  Most 
  of 
  the 
  Bardney 
  fossils 
  are 
  characteristic 
  of 
  Judd's 
  zone 
  of 
  

   cordati 
  Ammonites. 
  They 
  are 
  also 
  found 
  in 
  the 
  uppermost 
  zone 
  of 
  

   the 
  Oxford 
  Clay 
  of 
  Huntingdonshire. 
  

  

  * 
  Geology 
  of 
  Rutland, 
  &c. 
  (Mem. 
  Geol. 
  Surv.), 
  p. 
  232. 
  

  

  t 
  Geology 
  of 
  S.W. 
  Lincolnshire 
  (Mem. 
  Geol. 
  Surv.), 
  p. 
  70. 
  

  

  | 
  Some 
  doubt 
  having 
  been 
  expressed 
  as 
  to 
  the 
  correct 
  determination 
  of 
  these 
  

   fossils, 
  I 
  have 
  taken 
  the 
  opportunity, 
  since 
  the 
  paper 
  was 
  written, 
  of 
  closely 
  

   examining 
  them. 
  

  

  The 
  two 
  first-named 
  species 
  in 
  the 
  list 
  are 
  correctly 
  given. 
  

  

  The 
  specimen 
  from 
  which 
  Amm. 
  biplex 
  is 
  named 
  consists 
  of 
  a 
  portion 
  of 
  

   two 
  whorls. 
  The 
  whorls 
  are 
  round, 
  and 
  one 
  of 
  them 
  shows 
  a 
  well-marked 
  

   constriction. 
  Each 
  of 
  the 
  primary 
  ribs 
  is 
  divided 
  into 
  two 
  or 
  three 
  secondary 
  

   ones, 
  and 
  the 
  latter 
  are 
  considerably 
  smaller 
  than 
  the 
  former. 
  This 
  distin- 
  

   guishes 
  it 
  from 
  Amm. 
  biplex, 
  where 
  the 
  divided 
  and 
  undivided 
  ribs 
  are 
  equally 
  

   thick. 
  The 
  specimen 
  is 
  near 
  to, 
  if 
  not 
  identical 
  with, 
  Amm. 
  convolutus 
  dilatatus, 
  

   Quenst, 
  

  

  The 
  so-called 
  " 
  Amm. 
  macrocephahis 
  " 
  shows 
  the 
  back 
  and 
  a 
  portion 
  of 
  one 
  side 
  

   of 
  the 
  outer 
  whorl 
  only, 
  and 
  this 
  is 
  very 
  much 
  crushed. 
  The 
  primary 
  ribs 
  are 
  

   less 
  numerous 
  than 
  in 
  a 
  typical 
  example 
  of 
  this 
  species, 
  and 
  are 
  more 
  nearly 
  

   allied 
  to 
  those 
  of 
  a 
  mature 
  Amm. 
  marice. 
  The 
  specimen 
  is, 
  however, 
  too 
  badly 
  

   preserved 
  for 
  correct 
  determination. 
  

  

  • 
  The 
  remaining 
  species 
  {Amm. 
  arduennensis 
  and 
  Amm. 
  plicatilis) 
  may 
  be 
  

   correctly 
  named, 
  but 
  the 
  specimens 
  are 
  badly 
  preserved, 
  and 
  do 
  not 
  show 
  

   sufficient 
  characters 
  to 
  identify 
  them 
  with 
  any 
  degree 
  of 
  certainty. 
  

  

  § 
  Surv. 
  Mem. 
  sheet 
  83, 
  p. 
  77. 
  

  

  