﻿Systematic 
  Position 
  q/'Miolania. 
  139 
  

  

  frontals 
  with 
  the 
  palatines. 
  Besides, 
  the 
  fact 
  that 
  in 
  the 
  Trio- 
  

   nychoids 
  the 
  bony 
  connexion 
  between 
  the 
  prefrontals 
  and 
  the 
  

   vomer 
  may 
  be 
  present 
  or 
  absent, 
  is 
  sufficient 
  to 
  warn 
  us 
  against 
  

   attaching 
  great 
  importance 
  to 
  that 
  character. 
  And, 
  more- 
  

   over, 
  Dr. 
  Baur 
  is 
  not 
  justified 
  in 
  saying 
  that 
  the 
  prefrontals 
  are 
  

   connected 
  with 
  the 
  vomer 
  in 
  Miolania, 
  since, 
  so 
  far 
  as 
  the 
  

   material 
  in 
  the 
  British 
  Museum 
  shows, 
  the 
  connexion 
  may 
  

   have 
  been 
  just 
  as 
  well 
  with 
  the 
  palatines, 
  as 
  in 
  the 
  above- 
  

   named 
  Pleurodira. 
  

  

  Having 
  studied 
  the 
  palate 
  on 
  the 
  original 
  specimen 
  of 
  M. 
  

   platyceps 
  (Owen, 
  Phil. 
  Trans. 
  18S8, 
  pi. 
  xxxii.), 
  now 
  in 
  

   Sydney, 
  I 
  claim 
  to 
  be 
  better 
  informed 
  as 
  to 
  the 
  condition 
  of 
  

   the 
  pterygoids 
  than 
  my 
  critic, 
  who, 
  after 
  examining 
  merely 
  

   the 
  cast, 
  thinks 
  the 
  lateral 
  expansion 
  of 
  the 
  pterygoids 
  " 
  may 
  

   be 
  produced 
  by 
  crushing 
  of 
  the 
  edges." 
  I 
  can 
  confidently 
  

   state 
  that 
  the 
  left 
  pterygoid 
  figured 
  by 
  Owen 
  (/. 
  c.) 
  is 
  intact, 
  

   and 
  also 
  that 
  such 
  a 
  shape 
  as 
  it 
  shows 
  is 
  not 
  to 
  be 
  found 
  in 
  Tes- 
  

   tudo 
  or 
  in 
  any 
  other 
  Cryptodiran 
  (exclusive, 
  of 
  course, 
  of 
  the 
  

   Trionychoids). 
  Owing 
  to 
  the 
  condition 
  of 
  the 
  fossils 
  I 
  have 
  no 
  

   right, 
  any 
  more 
  than 
  Dr. 
  Baur, 
  to 
  be 
  absolutely 
  positive 
  in 
  my 
  

   statement 
  respecting 
  the 
  posterior 
  extension 
  of 
  the 
  pterygoids 
  ; 
  

   but 
  after 
  a 
  careful 
  comparison 
  with 
  numerous 
  types 
  of 
  Cryp- 
  

   todiran 
  and 
  Pleurodiran 
  Chelonians, 
  it 
  seems 
  to 
  me 
  extremely 
  

   probable 
  that 
  the 
  quadrate 
  did 
  join 
  the 
  basisphenoid, 
  as 
  in 
  

   Podocnemis. 
  1 
  have 
  already 
  indicated 
  the 
  reason 
  (P. 
  Z. 
  S. 
  

   1887, 
  p. 
  554) 
  why 
  the 
  pterygoids 
  are 
  not 
  turned 
  up 
  in 
  Mio- 
  

   lania. 
  

  

  The 
  back 
  of 
  the 
  skull 
  of 
  Miolania 
  is 
  as 
  typically 
  Pleuro- 
  

   diran 
  as 
  can 
  be, 
  and 
  totally 
  different 
  from 
  that 
  of 
  the 
  Testu- 
  

   dinidse. 
  A 
  complete 
  bony 
  ring, 
  which 
  I 
  decidedly 
  hold 
  to 
  be 
  

   formed 
  by 
  the 
  quadrate, 
  surrounds 
  the 
  ear-opening, 
  and 
  the 
  

   ear-chambers 
  are 
  otherwise 
  completely 
  open 
  behind. 
  

  

  How 
  Dr. 
  Baur 
  has 
  acquired 
  his 
  information 
  respecting 
  the 
  

   characters 
  of 
  the 
  Pleurodiran 
  cervical 
  vertebra? 
  as 
  compared 
  

   with 
  the 
  Cryptodiran 
  is 
  a 
  puzzle 
  to 
  me, 
  for 
  it 
  is 
  not 
  borne 
  out 
  

   by 
  an 
  examination 
  of 
  the 
  osteological 
  collection 
  in 
  the 
  British 
  

   Museum. 
  Better 
  than 
  any 
  lengthy 
  discussion, 
  the 
  following 
  

   figures 
  will 
  show 
  whether 
  Dr. 
  Baur 
  is 
  justified 
  in 
  stating 
  

   that 
  an 
  "atlas-ring'" 
  is 
  absent 
  in 
  the 
  Pleurodira 
  and 
  that 
  

   the 
  centrum 
  alone 
  supports 
  the 
  neuroids 
  of 
  the 
  atlas. 
  I 
  par- 
  

   ticularly 
  request 
  a 
  comparison 
  of 
  these 
  figures 
  with 
  his 
  defi- 
  

   nition 
  of 
  the 
  supposed 
  distinctive 
  characters 
  of 
  the 
  Pleurodiran 
  

   and 
  Cryptodiran 
  atlas. 
  

  

  With 
  regard 
  to 
  Miulania, 
  I 
  can 
  state 
  that 
  the 
  neuroids 
  of 
  

   the 
  atlas 
  are 
  supported 
  by 
  both 
  the 
  hypapophysis 
  (first 
  

   intercentrum) 
  and 
  the 
  centrum, 
  that 
  the 
  latter 
  articulated 
  

  

  10* 
  

  

  