﻿614 
  MR. 
  G. 
  W. 
  LAMPLT/GH 
  ON 
  THE 
  

  

  occurs 
  plentifully 
  in 
  the 
  " 
  Astarte-beds 
  " 
  of 
  that 
  zone: 
  but 
  these 
  

   have 
  been 
  identified 
  by 
  Professor 
  Pavlow 
  as 
  probably 
  Olcostephanus 
  

   subditus, 
  Traut., 
  a 
  shell 
  well 
  known 
  in 
  the 
  " 
  Upper 
  Volga 
  " 
  of 
  Russia. 
  

  

  Ammonites 
  maeginatus, 
  Phil. 
  

  

  In 
  the 
  extreme 
  forms 
  of 
  this 
  small 
  species 
  the 
  tubercles 
  around 
  

   the 
  umbilicus 
  develop 
  into 
  short 
  spines, 
  and 
  it 
  is 
  then 
  very 
  distinct 
  

   from 
  any 
  of 
  its 
  allies 
  ; 
  but, 
  as 
  noted 
  above, 
  the 
  less 
  pronounced 
  

   varieties 
  can 
  scarcely 
  be 
  distinguished 
  from 
  the 
  young 
  of 
  certain 
  

   varieties 
  of 
  Amm. 
  Astierianus. 
  It 
  seems 
  to 
  be 
  confined 
  to 
  the 
  upper 
  

   part 
  of 
  the 
  zone 
  of 
  Bel. 
  jaculum, 
  occurring 
  most 
  frequently 
  in 
  the 
  

   lower 
  part 
  of 
  the 
  Echinospatangus-bed, 
  though 
  nowhere 
  abundant. 
  

  

  Ammonites 
  nucleus, 
  Phil. 
  

  

  This 
  small 
  and 
  obscure 
  species 
  is 
  rather 
  abundant 
  in 
  the 
  upper 
  

   part 
  of 
  the 
  zone 
  of 
  Bel. 
  jaculum, 
  and 
  I 
  have 
  found 
  specimens 
  which 
  

   may 
  belong 
  to 
  it 
  as 
  high 
  as 
  the 
  " 
  Cement-beds." 
  Judd 
  has 
  pointed 
  

   out 
  the 
  relationship 
  of 
  this 
  species 
  to 
  Amm. 
  marginatus 
  ; 
  and 
  there 
  

   is 
  another 
  undescribed 
  form 
  or 
  variety 
  in 
  the 
  same 
  beds 
  which 
  also 
  

   comes 
  within 
  the 
  group. 
  

  

  If, 
  as 
  I 
  think, 
  the 
  area 
  has 
  undergone 
  very 
  few 
  physical 
  changes 
  

   during 
  a 
  long 
  period, 
  we 
  may 
  expect 
  to 
  find 
  many 
  slowly-changing 
  

   species 
  with 
  limits 
  difficult 
  to 
  define. 
  

  

  Ammonites 
  eotula, 
  Sow.* 
  

  

  This 
  is 
  a 
  well-marked 
  species, 
  very 
  distinct 
  from 
  any 
  of 
  those 
  

   above-named, 
  and 
  apparently 
  with 
  no 
  allies 
  in 
  the 
  clays. 
  It 
  is 
  

   nowhere 
  plentiful 
  ; 
  I 
  have 
  a 
  single 
  small 
  specimen 
  from 
  the 
  Com- 
  

   pound 
  Nodular 
  Band 
  (D 
  1) 
  and 
  others 
  from 
  the 
  Noricus-beds 
  (C 
  8 
  

   and 
  9), 
  but 
  it 
  is 
  in 
  the 
  "main 
  Speetonensis-bed" 
  (C 
  6) 
  that 
  it 
  is 
  

   easiest 
  to 
  find. 
  I 
  have 
  not 
  traced 
  it 
  higher. 
  

  

  Ammonites 
  Nistjs, 
  D'Orb. 
  (Judd) 
  ; 
  Amm. 
  planus, 
  Mant. 
  (Phillips). 
  

  

  This 
  shell 
  occurs 
  about 
  midway 
  in 
  the 
  zone 
  of 
  Bel. 
  jaculum, 
  but 
  

   it 
  is 
  very 
  rare. 
  D'Orbigny's 
  figure 
  and 
  description 
  of 
  Amm. 
  Nisus 
  

   indicate 
  a 
  smooth 
  shell, 
  but 
  the 
  Speeton 
  specimens 
  are 
  marked 
  with 
  

   faint 
  strise. 
  

  

  Criooeeas 
  or 
  Anctloceeas. 
  

  

  This 
  group 
  is 
  very 
  well 
  represented 
  at 
  Speeton, 
  but 
  it 
  is 
  not 
  often 
  

   that 
  the 
  specimens 
  are 
  well 
  preserved. 
  Several 
  very 
  distinct 
  species 
  

   occur, 
  five 
  being 
  named 
  in 
  Judd's 
  list, 
  besides 
  three 
  or 
  four 
  others 
  

   recognized 
  as 
  distinct, 
  but 
  not 
  identified. 
  

  

  That 
  author 
  seems 
  to 
  consider 
  that 
  the 
  whole 
  probably 
  belong 
  to 
  

   the 
  genus 
  Ancyloceras. 
  I 
  have 
  unfortunately 
  not 
  yet 
  learned 
  to 
  

   distinguish 
  these 
  species 
  well, 
  and 
  can 
  give 
  but 
  little 
  information 
  as 
  

   to 
  their 
  distribution. 
  The 
  lowest 
  level 
  to 
  which 
  I 
  have 
  traced 
  the 
  

   genus 
  is 
  the 
  Compound 
  Nodular 
  Band, 
  where 
  very 
  large 
  specimens 
  

  

  * 
  Recognized 
  by 
  Prof. 
  A. 
  Pavlow 
  as 
  probably 
  = 
  Olcostephanus 
  kasc/qmricus, 
  

   Traut 
  

  

  