﻿Vaianosaui'us 
  acutirosfcris, 
  BroUi. 
  299 
  

  

  bone 
  is 
  sliort, 
  and, 
  if 
  the 
  suture 
  is 
  correctly 
  recognized, 
  

   contributes 
  scarcely 
  at 
  all 
  to 
  the 
  tubera 
  basisphenoidales. 
  

  

  The 
  basisphenoid 
  is 
  a 
  large 
  bone, 
  whose 
  lowei- 
  surface 
  is 
  

   provided 
  with 
  two 
  very 
  pronounced 
  ridges, 
  which, 
  starting 
  

   at 
  the 
  tubera, 
  run 
  forwards 
  along 
  the 
  lower 
  surface 
  until 
  they 
  

   terminate 
  in 
  front 
  in 
  well-developed 
  basipterygoid 
  processes, 
  

   which 
  support 
  the 
  pterygoids 
  by 
  definite 
  articulations. 
  In 
  

   front 
  of 
  this 
  region 
  the 
  bone 
  is 
  concealed 
  by 
  matrix 
  and 
  the 
  

   pterygoids, 
  but 
  through 
  the 
  right 
  orbit 
  it 
  can 
  be 
  seen 
  to 
  be 
  

   continued 
  forwards 
  by 
  a 
  long 
  and 
  very 
  massive 
  parasphenoid, 
  

   whose 
  upper 
  border 
  is 
  grooved 
  in 
  front 
  and 
  supports 
  an 
  

   ethmoid, 
  the 
  visible 
  portion 
  of 
  which 
  forms 
  a 
  thin 
  median 
  

   septum. 
  In 
  front 
  the 
  parasphenoid 
  seems 
  to 
  be 
  clasped 
  by 
  

   an 
  ascending 
  flange 
  of 
  the 
  pterygoid. 
  

  

  Pterygoid. 
  

  

  The 
  pterygoid 
  is 
  the 
  usnal 
  triradiate 
  bone, 
  articulating 
  by 
  

   a 
  distinct 
  facet 
  with 
  the 
  basipterygoid 
  process 
  ; 
  the 
  anterior 
  

   ramus 
  runs 
  forward 
  as 
  a 
  plate 
  on 
  the 
  palate, 
  soon 
  joining 
  

   with 
  its 
  fellow, 
  so 
  as 
  to 
  leave 
  only 
  a 
  very 
  small 
  interptery- 
  

   goid 
  vacuity. 
  The 
  internal 
  ramus 
  forms 
  the 
  usual 
  process 
  

   against 
  the 
  side 
  of 
  the 
  lower 
  jaw, 
  but 
  the 
  structure 
  of 
  the 
  

   palate 
  cannot 
  be 
  made 
  out. 
  The 
  posterior 
  ramus 
  is 
  a 
  deep 
  

   thin 
  plate 
  running 
  backwards 
  behind 
  the 
  quadrate 
  to 
  the 
  

   extreme 
  hinder 
  end 
  of 
  the 
  skull; 
  on 
  the 
  left 
  side 
  it 
  can 
  be 
  

   distinctly 
  seen 
  to 
  come 
  into 
  contact 
  with 
  the 
  squamosal, 
  

   exactly 
  as 
  in 
  a 
  Stegocephalian. 
  

  

  Quadi'ate. 
  

  

  The 
  quadrate 
  is 
  represented 
  by 
  the 
  anterior 
  part 
  of 
  the 
  

   pterygoid 
  ramus, 
  which, 
  on 
  the 
  right 
  side, 
  is 
  clearly 
  seen 
  to 
  

   lie 
  on 
  the 
  outer 
  side 
  of 
  the 
  posterior 
  ramus 
  of 
  the 
  pterygoid 
  

   as 
  a 
  very 
  thin 
  film 
  of 
  bone. 
  The 
  articular 
  region 
  is 
  well 
  

   preserved 
  on 
  the 
  right 
  side. 
  There 
  is 
  a 
  pulley-shaped 
  

   condyle, 
  above 
  which 
  the 
  bone 
  rises 
  as 
  a 
  massive 
  sheet. 
  

   The 
  outer 
  surface 
  is 
  obviously 
  covered 
  by 
  membrane-bone, 
  

   the 
  squamosal, 
  and 
  probably 
  also 
  the 
  quadrato-jugal 
  ; 
  there 
  

   are, 
  however, 
  only 
  very 
  faint 
  traces 
  of 
  sutures, 
  and 
  no 
  

   quadrate 
  foramen. 
  

  

  On 
  the 
  inner 
  side, 
  well 
  above 
  the 
  condyle, 
  is 
  a 
  deep 
  and 
  

   very 
  well-marked 
  step, 
  which 
  can 
  only 
  have 
  served 
  for 
  the 
  

   articulation 
  of 
  the 
  outer 
  end 
  of 
  the 
  stapes. 
  

  

  