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  211 
  

  

  Type. 
  Portions 
  of 
  splenial 
  dentition 
  ; 
  Stuttgart 
  Museum. 
  

  

  The 
  largest 
  species 
  hitherto 
  discovered, 
  known 
  only 
  by 
  the 
  splenial 
  

   dentition. 
  Teeth 
  rounded 
  and 
  closely 
  arranged, 
  smooth 
  or 
  feebly 
  

   rugose, 
  with 
  traces 
  of 
  a 
  shallow 
  apical 
  pit 
  only 
  in 
  the 
  lateral 
  series. 
  

   Teeth 
  of 
  principal 
  series 
  at 
  least 
  twice 
  as 
  broad 
  as 
  long, 
  scarcely 
  if 
  

   at 
  all 
  arched, 
  and 
  almost 
  equally 
  blunt 
  at 
  each 
  extremity; 
  inner 
  

   series 
  very 
  small 
  and 
  irregular; 
  outer 
  teeth 
  in 
  four 
  irregular 
  

   series, 
  largest 
  and 
  broader 
  than 
  long 
  or 
  reniform 
  in 
  the 
  innermost 
  

   of 
  these, 
  smallest 
  in 
  the 
  second 
  and 
  third 
  series, 
  which 
  are 
  especially 
  

   irregular. 
  

  

  Form. 
  <$f 
  Loc. 
  Kimmeridgian 
  : 
  Switzerland; 
  N. 
  Germany 
  \ 
  

  

  P. 
  3742. 
  Imperfect 
  right 
  splenial 
  bone, 
  with 
  teeth 
  of 
  principal 
  and 
  

   first 
  outer 
  series 
  ; 
  Neuchatel. 
  Enniskillen 
  Coll. 
  

  

  P. 
  3743. 
  Plaster 
  cast 
  of 
  a 
  nearly 
  similar 
  specimen, 
  left 
  side 
  : 
  

   Soleure. 
  Enniskillen 
  Coll. 
  

  

  28379. 
  Imperfect 
  right 
  splenial 
  dentition, 
  of 
  small 
  size, 
  doubtfully 
  

   referable 
  to 
  young 
  of 
  this 
  species 
  ; 
  Soleure. 
  The 
  prin- 
  

   cipal 
  teeth 
  are 
  more 
  arcuated 
  than 
  usual 
  and 
  nearly 
  three 
  

   times 
  as 
  broad 
  as 
  long 
  ; 
  the 
  inner 
  teeth 
  are 
  minute 
  ; 
  the 
  

   second 
  outer 
  series 
  of 
  teeth 
  is 
  relatively 
  larger 
  than 
  in 
  

   the 
  typical 
  adult 
  dentition. 
  Purchased, 
  1853. 
  

  

  P. 
  7440. 
  Imperfect 
  left 
  splenial, 
  with 
  remains 
  of 
  dentary 
  externally 
  

   ornamented 
  with 
  fine 
  tubercles 
  ; 
  Langenberg, 
  Hanover. 
  

  

  Purchased, 
  1895. 
  

  

  Mesodon 
  affinis 
  (Pictet). 
  

   1860. 
  Pyenodus 
  affinis, 
  F. 
  J. 
  Pictet 
  {ex 
  Nicolet, 
  MS.), 
  Kept. 
  & 
  Poiss. 
  

   Foss. 
  Jura 
  Neuchatelois, 
  p. 
  50, 
  pis. 
  xii. 
  ; 
  xii. 
  bis, 
  pi. 
  xix. 
  fig. 
  1. 
  

  

  Type. 
  Splenial 
  dentition 
  ; 
  Neuchatel 
  Museum. 
  

  

  A 
  species 
  somewhat 
  smaller 
  than 
  M. 
  gigas, 
  also 
  known 
  only 
  by 
  

   the 
  mandibular 
  dentition, 
  which 
  closely 
  resembles 
  that 
  of 
  the 
  last- 
  

   named 
  species, 
  differing 
  (1) 
  in 
  the 
  relatively 
  larger 
  size 
  of 
  the 
  

   inner 
  series 
  of 
  teeth, 
  which 
  is 
  sometimes 
  duplicated, 
  and 
  (2) 
  in 
  the 
  

   relatively 
  smaller 
  size 
  and 
  rounded 
  form 
  of 
  the 
  teeth 
  in 
  the 
  inner- 
  

   most 
  of 
  the 
  outer 
  series. 
  

  

  Form. 
  &■ 
  Loc. 
  Kimmeridgian 
  : 
  Switzerland. 
  

  

  1 
  Detached 
  teeth 
  from 
  the 
  Kimmeridgian 
  and 
  Portlandiau 
  of 
  Boulogne 
  have 
  

   also 
  been 
  assigned 
  to 
  this 
  species 
  by 
  H. 
  E. 
  Sauvage, 
  Catal. 
  Poiss. 
  Form. 
  Second. 
  

   Boulonnais 
  (1867), 
  p. 
  25 
  ; 
  others 
  from 
  the 
  Diceraskalk 
  of 
  Kelheim, 
  Bavaria, 
  by 
  

   M. 
  Schlosser, 
  Palreontogr. 
  vol. 
  xxviii. 
  (1881), 
  p. 
  58, 
  pi. 
  viii. 
  figs. 
  4, 
  5; 
  others 
  

   from 
  the 
  Tithonian 
  of 
  Verona, 
  bj 
  P. 
  Bassani, 
  Atti 
  Soc. 
  Ital. 
  Sci. 
  Nat. 
  vol. 
  xxviii. 
  

   (1885), 
  p. 
  158, 
  pi. 
  ii.a. 
  figs. 
  10. 
  11. 
  

  

  p 
  2 
  

  

  