﻿142 
  PALEONTOLOGY 
  OF 
  LLLINOH 
  

  

  the 
  slope 
  terminating 
  in 
  a 
  narrow 
  depression, 
  which 
  is 
  bordered 
  by 
  

   the 
  more 
  or 
  less 
  well-defined 
  marginal 
  Mil 
  along 
  the 
  anterior 
  ar- 
  

   ticular 
  border, 
  that 
  behind 
  merging 
  into 
  the 
  wider 
  depression 
  which 
  

   is 
  bordered 
  by 
  the 
  narrow, 
  alate 
  lobe 
  of 
  the 
  posterior 
  border. 
  Other 
  

   dental 
  forms 
  of 
  the 
  mandibles 
  unknown. 
  

  

  Maxillary 
  posterior 
  teeth 
  trigonal 
  in 
  outline, 
  relatively 
  longer 
  and 
  

   less 
  strongly 
  arched 
  and 
  inrolled 
  than 
  the 
  opposed 
  mandibular 
  teeth. 
  

   Antero-lateral 
  border 
  gently 
  curved 
  sigmoidally 
  outward 
  and 
  slightly 
  

   forward, 
  proportionately 
  low 
  and 
  inbeveled, 
  defined 
  by 
  the 
  narrow, 
  

   rounded, 
  inbeveled 
  enamel 
  fold, 
  which 
  is 
  separated 
  from 
  the 
  Bhallow 
  

   basal 
  rim 
  by 
  a 
  narrow 
  furrow; 
  the 
  postero-lateral 
  border 
  more 
  ob- 
  

   liquely 
  converges 
  toward 
  the 
  outer 
  inrolled 
  margin 
  with 
  gentle 
  cur- 
  

   vature, 
  'usually 
  strongly 
  inbeveli 
  mal 
  enamel 
  contributing 
  

   a 
  relatively 
  wide 
  belt 
  inbeveled 
  to 
  the 
  deep, 
  more 
  or 
  Less 
  distinctly- 
  

   channeled 
  basal 
  portion, 
  which 
  meets 
  the 
  inferior 
  surface 
  of 
  the 
  

   tooth 
  in 
  an 
  obtuse 
  angulation: 
  inner 
  margin 
  very 
  obliquely 
  produced 
  

   from 
  the 
  slight 
  anterior 
  angle 
  to 
  the 
  base 
  of 
  the 
  coronal 
  prominence, 
  

   where 
  it 
  is 
  abruptly 
  deflected 
  with 
  a 
  cavity 
  in 
  passing 
  the 
  

   irior 
  coronal 
  depression 
  to 
  thi 
  ate 
  pos 
  Ltremity. 
  

   The 
  anterior 
  portion 
  of 
  the 
  crown 
  is 
  occupied 
  by 
  a 
  prominent 
  ri 
  

   the 
  more 
  or 
  less 
  rounded, 
  Bometimes 
  angular, 
  crest/ 
  culminating 
  

   nearest 
  the 
  antero-lateral 
  border, 
  to 
  whioh 
  it 
  is 
  steeply 
  sloped, 
  and 
  

   defined 
  by 
  the 
  shallows-depressed 
  bell 
  bordering 
  tl 
  

   posite 
  side 
  presenting 
  a 
  widi 
  . 
  de- 
  

   scending 
  into 
  the 
  posterior 
  depression, 
  whicb 
  is 
  bounded 
  by 
  the 
  more 
  

   or 
  le-s 
  strongly-upraised 
  posterior 
  alation. 
  The 
  character 
  of 
  the 
  

   anterior 
  teeth 
  associated 
  with 
  the 
  above 
  form 
  bat 
  en 
  deter- 
  

   mined. 
  

  

  superficial 
  oharact* 
  iciated 
  in 
  common 
  with 
  the 
  forms 
  

  

  above 
  notici 
  d 
  are 
  aubjecl 
  to 
  varia 
  i 
  the 
  

  

  i 
  sent. 
  While 
  the 
  normal 
  condition 
  of 
  I 
  mo 
  is 
  

  

  that 
  of 
  a 
  smooth, 
  finely 
  and 
  densely 
  pun 
  

  

  bain 
  Bpeoies 
  add 
  narrow, 
  impn 
  seed 
  bran 
  

   which 
  in 
  oth( 
  ime 
  th< 
  ide 
  ol 
  broad 
  undulatioi 
  

  

  rown 
  parallel 
  to 
  the 
  inner 
  mat 
  

   also, 
  in 
  oertain 
  Bpeoies, 
  mon 
  developed 
  longitudi- 
  

  

  nal 
  plica' 
  or 
  furrow.-, 
  which 
  an 
  m 
  the 
  lesfl 
  

  

  won 
  toward 
  th< 
  

  

  attention 
  of 
  naturalists, 
  and 
  hip 
  con- 
  

  

  > 
  the 
  

  

  