﻿432 
  X. 
  C. 
  MIALL 
  ON 
  THE 
  EEMAINS 
  OF 
  LABYKINTHODONTA 
  

  

  Plate 
  46. 
  figs. 
  1-5. 
  

  

  The 
  remarkable 
  relic 
  represented 
  in 
  fig. 
  1 
  has 
  been 
  the 
  basis 
  of 
  

   speculation 
  of 
  great 
  ingenuity. 
  Reasons 
  have 
  been 
  given 
  elsewhere 
  * 
  

   for 
  reconsidering 
  the 
  question. 
  The 
  collection 
  of 
  limb 
  -bones, 
  upon 
  

   which 
  so 
  much 
  stress 
  is 
  laid, 
  does 
  not 
  exhibit 
  a 
  single 
  Labyrintho- 
  

   dont 
  feature, 
  while 
  the 
  vertebrae 
  and 
  rhomboidal 
  sculptured 
  scale 
  

   associated 
  therewith, 
  far 
  from 
  confirming 
  Prof. 
  Owen's 
  interpretation, 
  

   would 
  almost 
  suffice 
  to 
  condemn 
  it. 
  This 
  fossil, 
  like 
  the 
  vertebrae, 
  

   ilium, 
  head 
  of 
  femur, 
  and 
  " 
  episternum" 
  already 
  referred 
  to, 
  would 
  

   not, 
  in 
  1841, 
  have 
  been 
  even 
  provisionally 
  referred 
  to 
  Labyrinthodon, 
  

   had 
  the 
  knowledge 
  which 
  we 
  now 
  possess 
  of 
  the 
  German 
  Triassic 
  

   Labyrinthodonts 
  been 
  in 
  existence, 
  or 
  had 
  it 
  been 
  suspected 
  that 
  

   the 
  Keuper 
  Sandstone 
  of 
  Warwick 
  might 
  contain 
  remains 
  of 
  true 
  

   reptiles. 
  

  

  Plate 
  46. 
  figs. 
  6, 
  7. 
  "Labyrinthodon 
  pachygnathus" 
  (Diadetogna- 
  

   thus 
  ?). 
  

  

  The 
  notch 
  in 
  the 
  left 
  side 
  of 
  the 
  principal 
  mass 
  of 
  bones 
  corre- 
  

   sponds 
  with 
  the 
  mandibular 
  articulation. 
  This 
  cavity 
  will 
  be 
  better 
  

   understood 
  if 
  the 
  bone 
  is 
  compared 
  with 
  the 
  same 
  part 
  of 
  Mastodon- 
  

   saurus 
  pachygnathus 
  (No. 
  3). 
  Differences 
  will 
  be 
  readily 
  perceived, 
  

   such 
  as 
  the 
  absence 
  in 
  the 
  present 
  fossil 
  of 
  the 
  tubercle 
  above 
  the 
  

   trochlea 
  of 
  the 
  quadrate, 
  and 
  the 
  greater 
  extension 
  of 
  the 
  quadrato- 
  

   jugal 
  behind 
  the 
  glenoid 
  cavity. 
  On 
  the 
  other 
  hand, 
  this 
  fragment 
  

   of 
  the 
  skull 
  agrees 
  remarkably 
  well 
  with 
  the 
  mandibular 
  ramus 
  of 
  

   Diadetognathus 
  varvicensis, 
  and 
  I 
  believe 
  that 
  it 
  belongs 
  to 
  that 
  

  

  Fig. 
  3. 
  — 
  Section 
  of 
  the 
  mandibular 
  articulation 
  of 
  Diadetognathus. 
  

   (Explanation 
  as 
  before, 
  see 
  fig. 
  1, 
  p. 
  420.) 
  

  

  ^..., 
  ^ 
  

  

  species. 
  The 
  sculpture 
  has 
  the 
  same 
  general 
  character 
  as 
  in 
  Diade- 
  

   tognathus 
  ; 
  but, 
  in 
  the 
  absence 
  of 
  more 
  distinctive 
  features, 
  this 
  

   would 
  not 
  suffice 
  to 
  indicate 
  the 
  genus. 
  The 
  notch 
  near 
  the 
  right- 
  

   hand 
  bottom 
  corner 
  of 
  the 
  figure 
  probably 
  marks 
  the 
  position 
  of 
  the 
  

   auditory 
  fossa. 
  A 
  suture, 
  dividing 
  the 
  quadrato-jugal 
  from 
  the 
  

   supratemporal, 
  intersects 
  the 
  fossil 
  from 
  top 
  to 
  bottom, 
  when 
  placed 
  

   in 
  the 
  figured 
  position. 
  The 
  upper 
  (anterior) 
  part 
  of 
  the 
  suture 
  lies 
  

  

  * 
  British 
  Association 
  Eeport, 
  1873, 
  p. 
  243. 
  

  

  