﻿VERTEBRATES. 
  83 
  

  

  be 
  a 
  strong 
  resemblance 
  to 
  the 
  large 
  tooth 
  found 
  at 
  Oreton, 
  in 
  

   Shropshire, 
  drawings 
  of 
  which 
  were 
  kindly 
  communicated 
  by 
  Lord 
  

   Enniskillen, 
  showing 
  a 
  tooth 
  of 
  nearly 
  equal 
  dimensions 
  and 
  differ- 
  

   ing 
  chiefly 
  from 
  the 
  present 
  form 
  in 
  the 
  less 
  prominent 
  and 
  well 
  

   defined 
  posterior 
  coronal 
  lobe, 
  and 
  perhaps 
  less 
  massive 
  proportions 
  

   in 
  the 
  region 
  of 
  the 
  coronal 
  prominence. 
  The 
  latter 
  form 
  we 
  are 
  

   not 
  aware 
  has 
  been 
  described. 
  The 
  distinctions 
  of 
  the 
  present 
  form, 
  

   compared 
  with 
  the 
  smaller 
  forms 
  hereinafter 
  described, 
  need 
  not 
  

   receive 
  further 
  notice 
  in 
  this 
  place. 
  The 
  Belgian 
  Carboniferous 
  

   tooth 
  described 
  by 
  Dr. 
  L. 
  de 
  Koninck 
  under 
  the 
  name 
  Streblodus 
  

   tenerrimus, 
  is 
  under 
  medium 
  size, 
  and 
  is 
  further 
  distinguished 
  from 
  

   the 
  present 
  tooth 
  by 
  its 
  relatively 
  narrower 
  posterior 
  prominence 
  

   and 
  stronger 
  spiral 
  inrollment. 
  

  

  Geological 
  position 
  and 
  locality: 
  This 
  unique 
  example 
  was 
  derived 
  

   from 
  the 
  uppermost 
  bed 
  of 
  the 
  Kinderhook 
  series 
  exposed 
  in 
  the 
  

   banks 
  of 
  Long 
  Creek, 
  a 
  tributary 
  of 
  Skunk 
  river, 
  Des 
  Moines 
  Co., 
  

   Iowa. 
  

  

  Vaticinodus 
  jhscrepans, 
  St. 
  J. 
  and 
  W. 
  

  

  PI. 
  Ill, 
  Fig. 
  2, 
  3. 
  

  

  The 
  collections 
  contain 
  three 
  or 
  four 
  examples 
  of 
  maxillary 
  pos- 
  

   terior 
  teeth, 
  which, 
  although 
  in 
  a 
  fragmentary 
  state 
  of 
  preservation, 
  

   apparently 
  differ 
  from 
  any 
  of 
  the 
  associated 
  species 
  thus 
  far 
  made 
  

   known 
  from 
  the 
  Upper 
  Burlington 
  horizon, 
  in 
  which 
  the 
  present 
  

   form 
  was 
  discovered 
  by 
  Mr. 
  Springer. 
  Tbey 
  are 
  evidently 
  referable 
  

   to 
  the 
  above 
  genus, 
  and 
  offer 
  the 
  following 
  distinctive 
  features, 
  es- 
  

   pecially 
  compared 
  with 
  the 
  much 
  more 
  prevalent 
  forms 
  of 
  Stenop- 
  

   terodus 
  planus, 
  with 
  which 
  they 
  are 
  associated, 
  and 
  for 
  which 
  they 
  

   are 
  most 
  liable 
  to 
  be 
  mistaken: 
  Attaining 
  a 
  larger 
  size, 
  the 
  teeth 
  

   are 
  specially 
  distinguished 
  by 
  the 
  much 
  more 
  rapid 
  convergence 
  

   of 
  the 
  postero-lateral 
  border, 
  and 
  the 
  consequent 
  greater 
  ob- 
  

   liquity 
  of 
  the 
  coronal 
  prominence, 
  which 
  presents 
  a 
  broad, 
  very 
  

   slightly 
  convex 
  posterior 
  slope, 
  and 
  abrupt 
  declivity 
  in 
  front, 
  where 
  

   it 
  is 
  defined 
  by 
  a 
  slight 
  angulation 
  from 
  the 
  plain 
  anterior 
  area. 
  

   The 
  inner 
  margin 
  is 
  more 
  sharply 
  rounded 
  in 
  the 
  region 
  of 
  the 
  base 
  

   of 
  the 
  coronal 
  prominence, 
  slightly 
  concave 
  or 
  constricted 
  in 
  front, 
  

   and 
  thence 
  to 
  the 
  obtuse 
  anterior 
  angle 
  it 
  pursues 
  a 
  gently 
  arched 
  

   or 
  nearly 
  direct 
  course. 
  The 
  coronal 
  surface 
  shows 
  minute, 
  closely 
  

  

  

  