﻿430 
  L. 
  C. 
  MIALL 
  OS 
  THE 
  REMAINS 
  OF 
  LA3TRINTHODONTA 
  

  

  12. 
  Mastodonsaurtjs 
  giganteus, 
  Jager 
  — 
  part 
  of 
  left 
  lateral 
  thoracic 
  

   plate. 
  "Warwick 
  (Dr. 
  Lloyd). 
  Fig. 
  2. 
  

  

  This 
  agrees 
  so 
  well, 
  hoth 
  in 
  dimensions 
  and 
  sculpture, 
  with 
  the 
  

   "Wiirttemberg 
  fossil 
  figured 
  by 
  Yon 
  Meyer 
  and 
  Plieninger* 
  that 
  I 
  

   have 
  referred 
  it 
  to 
  the 
  same 
  species. 
  The 
  thin, 
  expanded, 
  and 
  non- 
  

   sculptured 
  outer 
  margin 
  of 
  the 
  plate 
  is 
  well 
  displayed 
  by 
  our 
  example. 
  

   If 
  the 
  specific 
  determination 
  is 
  correct, 
  the 
  dotted 
  outline 
  of 
  the 
  

   Palaontologie 
  Wurttembergs 
  requires 
  to 
  be 
  carried 
  further 
  out. 
  

  

  Measurements 
  : 
  — 
  in. 
  

  

  Greatest 
  width 
  (imperfect) 
  9| 
  

  

  Greatest 
  width 
  of 
  sculptured 
  tract 
  6 
  

  

  Thickness 
  at 
  the 
  inner 
  side, 
  about 
  | 
  

  

  In 
  the 
  "Warwick 
  collection 
  there 
  are 
  also 
  six 
  fragments 
  of 
  bones 
  

   belonging 
  to 
  the 
  limbs. 
  Some 
  of 
  these, 
  in 
  all 
  probability, 
  are 
  Laby- 
  

   rinthodont 
  ; 
  but 
  in 
  the 
  absence 
  of 
  evidence 
  derived 
  either 
  from 
  their 
  

   association 
  with 
  determinable 
  remains 
  or 
  from 
  comparison 
  with 
  parts 
  

   so 
  authenticated, 
  it 
  is 
  safer 
  to 
  withhold 
  description 
  for 
  the 
  present. 
  

  

  I 
  shall 
  not 
  presume 
  to 
  pass 
  a 
  general 
  opinion 
  upon 
  Prof. 
  Owen's 
  

   two 
  Memoirs, 
  " 
  The 
  Labyrinthodons 
  of 
  Wirtemberg 
  and 
  Warwick- 
  

   shire 
  " 
  and 
  " 
  On 
  Species 
  of 
  Labyrinthodon 
  from 
  Warwickshire 
  "f. 
  

   The 
  new 
  material 
  accumulated 
  since 
  1842, 
  in 
  England, 
  and 
  especially 
  

   in 
  Germany, 
  renders 
  it 
  possible 
  to 
  amend 
  the 
  determinations 
  of 
  parti- 
  

   cular 
  bones 
  ; 
  and 
  to 
  this 
  task 
  I 
  shall, 
  as 
  far 
  as 
  possible, 
  confine 
  myself. 
  

  

  Plate 
  43. 
  figs. 
  1-3, 
  p. 
  516. 
  Labyrinthodon^ 
  leptognathus, 
  Owen. 
  

  

  So 
  long 
  ago 
  as 
  1844 
  Yon 
  Meyer 
  gave 
  excellent 
  reasons 
  for 
  regard- 
  

   ing 
  this 
  fragment 
  of 
  the 
  fore 
  part 
  of 
  the 
  skull 
  as 
  distinct 
  from 
  

   Mastodonsaurus, 
  or 
  any 
  other 
  Labyrinthodont 
  then 
  described 
  J. 
  It 
  

   is 
  only 
  one 
  fourth 
  of 
  the 
  size 
  of 
  the 
  corresponding 
  part 
  of 
  the 
  large 
  

   skull 
  of 
  Mastodonsaurus 
  giganteus, 
  from 
  Gaildorf 
  ; 
  the 
  palatal 
  surface 
  

   is 
  more 
  completely 
  closed 
  by 
  bone, 
  the 
  maxillary 
  teeth 
  are 
  hardly 
  

   smaller 
  absolutely, 
  and 
  are 
  therefore 
  relatively 
  much 
  larger 
  than 
  in 
  

   Mastodonsaurus 
  ; 
  and 
  there 
  is 
  a 
  tusk 
  in 
  the 
  maxillary 
  series. 
  The 
  

   mucous 
  canals, 
  visible 
  on 
  the 
  upper 
  surface, 
  are 
  similar 
  to 
  those 
  of 
  

   Mastodonsaurus, 
  but 
  not 
  identical. 
  There 
  is 
  a 
  transverse 
  row 
  of 
  

   small 
  vomerine 
  teeth, 
  as 
  in 
  Metopias, 
  and 
  a 
  longitudinal 
  row 
  internal 
  

   to 
  the 
  posterior 
  nasal 
  aperture, 
  as 
  in 
  Trematosaurus. 
  Both 
  series 
  

   occur 
  in 
  the 
  palate 
  of 
  Mastodonsaurus 
  §. 
  This 
  fossil 
  is 
  the 
  type 
  of 
  a 
  

   distinct 
  genus 
  and 
  species, 
  for 
  which 
  the 
  name 
  of 
  Labyrinthodon 
  

   leptognathus, 
  Owen, 
  may 
  be 
  retained. 
  

  

  Plate 
  43. 
  fig. 
  11. 
  p. 
  530. 
  

  

  This 
  fragment 
  is 
  described 
  as 
  the 
  anterior 
  frontal 
  of 
  Labyrinthodon 
  

   pachygnathus. 
  The 
  deep 
  pit, 
  in 
  what 
  is 
  taken 
  for 
  the 
  orbital 
  plate, 
  

  

  * 
  Palaontologie 
  Wurttembergs, 
  t. 
  iv. 
  figs. 
  1 
  & 
  2. 
  

  

  t 
  Geol. 
  Trans. 
  2nd 
  series, 
  vol. 
  vi. 
  pp. 
  503-543 
  (1842). 
  

  

  X 
  Palaontologie 
  Wiirttembergs, 
  p. 
  36. 
  

  

  § 
  See 
  Von 
  Meyer's 
  ' 
  Saurier 
  des 
  Musckelkalkes,' 
  t. 
  61. 
  fig. 
  5, 
  and 
  t. 
  64. 
  fig. 
  16. 
  

  

  