﻿122-D 
  THE 
  EXTINCT 
  BATRACHIA, 
  REPTILIA 
  

  

  face, 
  probably 
  anterior, 
  presents 
  a 
  longitudinal 
  groove; 
  one 
  broad 
  face, 
  perhaps 
  the 
  exter- 
  

   nal, 
  a 
  convex 
  articular 
  surface. 
  The 
  metatarsal 
  face 
  is 
  slightly 
  concave. 
  

  

  The 
  metatarsus 
  which 
  relates 
  to 
  the 
  above, 
  therefore 
  the 
  exterior, 
  is 
  much 
  like 
  that 
  of 
  

   the 
  Alligator. 
  The 
  planes 
  of 
  the 
  two 
  extremities 
  are 
  nearly 
  at 
  right 
  angles 
  to 
  each 
  other. 
  

   The 
  proximal 
  extremity 
  is 
  sub-triangular 
  with 
  an 
  external 
  angle 
  prolonged, 
  and 
  the 
  poste- 
  

   rior 
  outline 
  longest 
  and 
  slightly 
  sigmoid. 
  The 
  shank 
  has 
  a 
  large 
  medullary 
  cavity; 
  the 
  

   distal 
  articular 
  surface 
  is 
  sub-truncate, 
  and 
  the 
  ligamentous 
  pit 
  very 
  shallow, 
  indicating 
  ab- 
  

   sence 
  of 
  much 
  flexure 
  at 
  that 
  point. 
  The 
  convex 
  external 
  face 
  of 
  the 
  cuboid, 
  indicates 
  

   the 
  existence 
  of 
  a 
  rudimental 
  external 
  digit 
  in 
  the 
  usual 
  place 
  of 
  the 
  fifth 
  ; 
  it 
  may 
  have 
  

   been 
  but 
  a 
  part 
  of 
  a 
  metatarsus, 
  as 
  in 
  the 
  crocodiles. 
  No 
  trace 
  remains. 
  Two 
  other 
  digits 
  

   have 
  left 
  their 
  remains. 
  Of 
  these 
  the 
  median 
  is 
  so 
  much 
  larger 
  than 
  those 
  on 
  each 
  side 
  of 
  

   it, 
  as 
  to 
  render 
  it 
  probable 
  that 
  this 
  animal 
  possessed 
  but 
  three 
  developed 
  toes 
  ; 
  in 
  those 
  

   types 
  with 
  a 
  larger 
  number, 
  the 
  two 
  median 
  at 
  least, 
  are 
  of 
  proportions 
  more 
  nearly 
  simi- 
  

   lar 
  to 
  each 
  other. 
  

  

  One 
  phalange 
  of 
  the 
  middle 
  toe 
  is 
  of 
  a 
  stout 
  and 
  somewhat 
  compressed 
  form. 
  Two 
  of 
  

   the 
  inner 
  toe 
  are 
  more 
  slender; 
  the 
  articular 
  ligamentous 
  pit 
  is 
  distinct 
  in 
  those 
  of 
  both 
  

   and 
  the 
  condyle 
  convex, 
  indicating 
  extensive 
  flexure. 
  All 
  are 
  hollow. 
  

  

  The 
  disproportion 
  between 
  the 
  lengths 
  of 
  the 
  limbs 
  is 
  not 
  readily 
  ascertained 
  ; 
  it 
  is 
  

   evidently 
  not 
  nearly 
  so 
  great 
  as 
  in 
  the 
  Lselaps, 
  perhaps 
  not 
  greater 
  than 
  in 
  many 
  

   modern 
  Lacertilia. 
  

  

  Ribs 
  are 
  represented 
  by 
  several 
  fragments, 
  one 
  perhaps 
  a 
  half. 
  They 
  display 
  both 
  

   capitular 
  and 
  tubercular 
  articulations, 
  the 
  former 
  apparently 
  much 
  the 
  more 
  extensive. 
  

   The 
  head 
  and 
  shaft 
  of 
  the 
  ribs 
  are 
  compressed, 
  and 
  the 
  capitular 
  prolongation 
  is 
  as 
  deep 
  

   as 
  the 
  base 
  of 
  the 
  shaft. 
  The 
  latter 
  has 
  a 
  groove 
  along 
  its 
  dorsal 
  line 
  for 
  the 
  proximal 
  

   two-fifths 
  the 
  length. 
  It 
  is 
  hollow, 
  the 
  medullary 
  cavity 
  being 
  equal 
  in 
  diameter 
  to 
  the 
  

   wall 
  surrounding 
  it. 
  

  

  A 
  Y-shaped 
  bone 
  with 
  rather 
  long 
  stem 
  has 
  left 
  an 
  impression. 
  The 
  limbs 
  of 
  the 
  

   figure 
  are 
  slightly 
  unequal 
  in 
  length. 
  Can 
  it 
  be 
  a 
  hatchet 
  bone 
  of 
  the 
  cervical 
  vertebrae'? 
  

  

  The 
  pelvis 
  is 
  only 
  represented 
  by 
  a 
  considerable 
  portion 
  of 
  both 
  ossa 
  ischii. 
  These 
  

   indicate 
  a 
  remarkable 
  peculiarity 
  of 
  the 
  type, 
  and 
  explain 
  the 
  structure 
  in 
  La?laps 
  and 
  

   some 
  other 
  Dinosauria. 
  The 
  portions 
  preserved 
  are 
  the 
  distal 
  and 
  median, 
  with 
  the 
  im- 
  

   pressions 
  of 
  the 
  more 
  proximal 
  in 
  the 
  matrix. 
  The 
  former 
  consists 
  of 
  two 
  stout 
  rod-like 
  

   elements, 
  having 
  a 
  triangular 
  section, 
  the 
  superior 
  and 
  inner 
  faces 
  being 
  plane, 
  the 
  exte- 
  

   rior 
  convex. 
  The 
  two 
  interior 
  are 
  in 
  contact 
  throughout 
  the 
  straight 
  portion 
  of 
  the 
  

   bones. 
  The 
  extremity 
  is 
  convex 
  and 
  enlarged, 
  especially 
  downwards, 
  and 
  the 
  two 
  are 
  

   separated 
  by 
  a 
  deep 
  groove, 
  giving 
  a 
  section 
  of 
  the 
  extremity 
  the 
  form 
  of 
  an 
  oo 
  . 
  At 
  the 
  

   point 
  of 
  divergence 
  the 
  stylus 
  is 
  flattened, 
  while 
  the 
  divergent 
  portions 
  are 
  more 
  flattened, 
  

  

  