﻿EEOM 
  THE 
  KEUPEB, 
  SANDSTONE 
  OE 
  WARWICK. 
  423 
  

  

  articular 
  element. 
  It 
  is 
  comparatively 
  smooth 
  from 
  the 
  condyle 
  for- 
  

   wards, 
  being 
  overlapped 
  to 
  a 
  considerable 
  extent 
  by 
  the 
  lateral 
  expan- 
  

   sion 
  of 
  the 
  skull 
  (see 
  woodcut, 
  fig. 
  1). 
  A 
  shallow 
  mucous 
  canal 
  (h. 
  g.) 
  

   bounds 
  the 
  sculptured 
  tract 
  above 
  ; 
  it 
  has 
  a 
  horizontal 
  direction, 
  and 
  

   nearly 
  coincides 
  with 
  the 
  suture 
  between 
  the 
  angular 
  and 
  articular 
  

   bones. 
  A 
  much 
  deeper 
  and 
  better 
  defined 
  mucous 
  canal 
  (d. 
  g.), 
  about 
  

   half 
  an 
  inch 
  wide, 
  and 
  nearly 
  semicircular 
  in 
  section, 
  curves 
  down- 
  

   wards 
  and 
  forwards 
  from 
  behind 
  the 
  condyle 
  to 
  near 
  the 
  centre 
  of 
  ra- 
  

   diation 
  of 
  the 
  subcutaneous 
  sculpture. 
  At 
  about 
  this 
  point 
  it 
  turns 
  

   inwards, 
  as 
  if 
  to 
  cross 
  the 
  inferior 
  border, 
  but 
  loses 
  itself 
  without 
  im- 
  

   pressing 
  the 
  smooth 
  internal 
  surface 
  of 
  the 
  ramus. 
  Into 
  this 
  descend- 
  

   ing 
  canal 
  the 
  horizontal 
  canal 
  previously 
  described 
  opens. 
  The 
  angu- 
  

   lari-articular 
  suture 
  crosses 
  the 
  descending 
  canal 
  nearly 
  at 
  the 
  same 
  

   point 
  (that 
  is, 
  in 
  the 
  middle 
  of 
  its 
  course), 
  curving 
  thence 
  upwards, 
  

   and 
  terminating 
  in 
  the 
  fractured 
  extremity 
  of 
  the 
  large 
  and 
  strong 
  

   postarticular 
  process. 
  Above 
  the 
  suture, 
  in 
  the 
  part 
  of 
  the 
  ramus 
  

   behind 
  the 
  descending 
  canal, 
  is 
  a 
  small 
  triangular 
  patch 
  of 
  sculpture 
  ; 
  

   beneath 
  it, 
  the 
  narrow 
  space 
  between 
  the 
  canal 
  and 
  the 
  rounded 
  

   postero-inferior 
  border 
  of 
  the 
  ramus 
  is 
  quite 
  smooth. 
  A 
  number 
  of 
  

   vascular 
  foramina 
  appear 
  upon 
  the 
  external 
  surface 
  of 
  the 
  ramus, 
  

   especially 
  in 
  the 
  neighbourhood 
  of 
  the 
  mucous 
  canals. 
  Three 
  of 
  

   these, 
  situate 
  upon 
  the 
  lower, 
  or 
  angular, 
  portion 
  of 
  the 
  descending 
  

   canal, 
  open 
  upwards 
  and 
  backwards 
  ; 
  while 
  those 
  upon 
  the 
  articular 
  

   portion 
  of 
  the 
  same 
  canal, 
  and 
  upon 
  the 
  horizontal 
  canal, 
  look 
  for- 
  

   wards 
  and 
  downwards. 
  

  

  The 
  ramus 
  terminates 
  behind 
  in 
  a 
  smooth 
  and 
  rounded 
  edge, 
  

   which 
  curves 
  gently 
  and 
  continuously 
  upwards 
  from 
  the 
  lower 
  

   end 
  of 
  the 
  descending 
  canal 
  to 
  the 
  tip 
  of 
  the 
  postarticular 
  process. 
  

  

  The 
  top 
  of 
  the 
  ramus 
  is 
  occupied 
  by 
  a 
  coronoid 
  ridge, 
  which 
  is 
  

   about 
  4 
  inches 
  long, 
  and 
  about 
  a 
  quarter 
  of 
  an 
  inch 
  high. 
  It 
  passes 
  

   behind 
  into 
  the 
  anterior 
  of 
  two 
  transverse 
  ascending 
  processes 
  which 
  

   bound 
  the 
  articular 
  cavity 
  ; 
  towards 
  the 
  broken 
  anterior 
  end 
  of 
  the 
  

   fossil 
  it 
  gradually 
  sinks 
  into 
  a 
  groove. 
  This 
  groove 
  was 
  probably 
  

   occupied 
  by 
  the 
  dentary 
  bone, 
  which 
  also 
  filled 
  part 
  of 
  the 
  angle 
  now 
  

   seen 
  between 
  the 
  coronoid 
  ridge 
  and 
  the 
  smooth 
  outer 
  surface 
  of 
  the 
  

   top 
  of 
  the 
  ramus. 
  The 
  surface 
  of 
  the 
  ridge 
  is 
  smooth, 
  except 
  for 
  

   longitudinal 
  striae. 
  Other 
  examples 
  of 
  Mastodonsaurus 
  show 
  that 
  the 
  

   dentary 
  bone 
  extended 
  backwards 
  nearly 
  as 
  far 
  as 
  the 
  centre 
  of 
  radia- 
  

   tion 
  of 
  sculpture 
  upon 
  the 
  angular 
  bone, 
  and 
  terminated 
  in 
  a 
  point. 
  

  

  The 
  condyle 
  and 
  postarticular 
  process 
  are 
  those 
  of 
  Mastodonsaurus, 
  

   though 
  much 
  smaller 
  than 
  in 
  M. 
  giganteus. 
  Though 
  not 
  quite 
  per- 
  

   fect, 
  the 
  present 
  fossil 
  exhibits 
  some 
  important 
  features 
  more 
  clearly 
  

   than 
  any 
  of 
  the 
  Stuttgard 
  specimens. 
  The 
  articular 
  cavity 
  (Art) 
  is 
  

   saddle-shaped, 
  being 
  concave 
  from 
  before 
  backwards, 
  and 
  convex 
  

   from 
  side 
  to 
  side. 
  The 
  inner 
  half 
  or 
  so 
  of 
  the 
  original 
  surface 
  has 
  

   been 
  broken 
  away. 
  Two 
  transverse 
  ridges 
  define 
  the 
  cavity. 
  Of 
  

   these 
  the 
  posterior 
  is 
  the 
  higher, 
  and 
  extends 
  completely 
  across 
  ; 
  the 
  

   anterior 
  bounds 
  only 
  the 
  inner 
  half 
  of 
  the 
  cavity. 
  The 
  articular 
  

   surface 
  rests 
  in 
  part 
  upon 
  a 
  strong 
  internal 
  buttress. 
  The 
  broken 
  

   mass 
  which 
  represents 
  this 
  buttress 
  now 
  extends 
  for 
  an 
  inch 
  beyond 
  

  

  