﻿104 
  

  

  THE 
  EXTINCT 
  BATRACHIA, 
  REPTILIA 
  

  

  Left 
  Femur. 
  — 
  The 
  head 
  and 
  summit 
  of 
  the 
  great 
  trochanter, 
  and 
  the 
  posterior 
  portions 
  of 
  the 
  condyles, 
  are 
  broken 
  

   away. 
  The 
  shaft 
  is 
  rather 
  slender, 
  and 
  is 
  strongly 
  arched 
  forwards 
  and 
  slightly 
  outwards. 
  The 
  third 
  trochanter 
  is 
  

   on 
  the 
  posterior 
  face, 
  is 
  turned 
  inwards, 
  and 
  marks 
  one-third 
  the 
  length 
  of 
  the 
  shaft 
  from 
  the 
  supposed 
  position 
  of 
  

   the 
  head. 
  Just 
  below 
  it 
  the 
  shaft 
  is 
  cyclo-trigonal, 
  while 
  for 
  a 
  short 
  distance 
  above 
  the 
  condyles 
  it 
  is 
  flattened 
  ante- 
  

   roposteriorly. 
  It 
  is 
  strongly 
  concave 
  between 
  the 
  condyloid 
  ridges 
  at 
  the 
  distal 
  end. 
  At 
  this 
  place 
  the 
  external 
  face 
  

   is 
  convex, 
  the 
  internal 
  concave 
  as 
  high 
  as 
  a 
  point 
  a 
  little 
  more 
  than 
  a 
  fourth 
  the 
  total 
  length. 
  The 
  concavity 
  is 
  sepa- 
  

   rated 
  from 
  the 
  anterior 
  face 
  by 
  a 
  strong 
  ridge 
  which 
  is 
  partly 
  broken 
  away. 
  The 
  anterior 
  surface 
  is 
  turned 
  posteriorly 
  

   to 
  the 
  external 
  condyle, 
  while 
  it 
  is 
  concave 
  and 
  turned 
  forwards 
  to 
  the 
  internal 
  condyle. 
  

  

  The 
  posterior 
  portions 
  of 
  the 
  two 
  condyles 
  are 
  broken 
  away, 
  so 
  as 
  to 
  give 
  their 
  remaining 
  portions 
  almost 
  exactly 
  

   the 
  form 
  of 
  the 
  head 
  of 
  the 
  femur 
  in 
  Hadrosaurus 
  and 
  Iguanodon. 
  The 
  dense 
  layer 
  of 
  the 
  remaining 
  portions 
  is 
  

   much 
  worn 
  away, 
  but 
  enough 
  remains 
  to 
  show 
  that 
  the 
  external 
  was 
  rather 
  the 
  more 
  prominent. 
  The 
  trochlear 
  and 
  

   popliteal 
  concavities 
  approach 
  much 
  nearer 
  together 
  than 
  in 
  Megalosaurus, 
  causing 
  a 
  greater 
  attenuation 
  of 
  the 
  

   basis 
  for 
  the 
  condyles. 
  It 
  cannot 
  be 
  ascertained 
  whether 
  the 
  external 
  condyle 
  bore 
  the 
  small 
  process 
  behind 
  seen 
  in 
  

   Megalosaurus. 
  

  

  The 
  neck 
  is 
  much 
  compressed 
  anteroposteriorly, 
  and 
  extends 
  much 
  interior 
  to 
  the 
  line 
  of 
  the 
  shaft. 
  The 
  poste- 
  

   rior 
  face 
  is 
  regularly 
  convex, 
  and 
  then 
  turns 
  into 
  the 
  transversely 
  convex 
  exterior, 
  which 
  is 
  divided 
  above 
  by 
  the 
  

   groove 
  that 
  separates 
  the 
  external 
  trochanter. 
  The 
  broad 
  posterior 
  face 
  narrows 
  below 
  this 
  trochanter, 
  and 
  presents 
  

   a 
  strong 
  convexity 
  posteriorly, 
  opposite 
  the 
  upper 
  portion 
  of 
  the 
  third 
  trochanter. 
  The 
  outer 
  trochanter 
  has 
  a 
  flat 
  

   anterior 
  face, 
  and 
  presents 
  a 
  sharp 
  margin 
  inwards. 
  It 
  is 
  separated 
  from 
  the 
  neck 
  by 
  a 
  deep 
  longitudinal 
  concavity. 
  

   It 
  is 
  probably 
  much 
  shorter 
  than 
  the 
  head 
  of 
  the 
  femur, 
  about 
  as 
  in 
  Megalosaurus. 
  

  

  In. 
  

   Length 
  of 
  femur 
  restored, 
  35.5 
  

  

  " 
  actual, 
  32. 
  

  

  Transverse 
  extent 
  of 
  condyles, 
  G.45 
  

  

  Posterior 
  breadth 
  of 
  neck, 
  6.5 
  

  

  Anterior 
  " 
  of 
  great 
  trochanter. 
  3.25 
  

  

  Diameter 
  neck 
  and 
  " 
  " 
  4.5 
  

  

  " 
  anterior 
  groove 
  between 
  them 
  (medially), 
  1.5 
  

  

  Circumference 
  shaft 
  at 
  middle, 
  11. 
  

  

  This 
  element, 
  compared 
  with 
  that 
  of 
  Megalosaurus, 
  differs 
  in 
  its 
  considerably 
  more 
  slender 
  form, 
  and 
  in 
  its 
  curva- 
  

   ture. 
  The 
  femur 
  of 
  the 
  latter 
  genus 
  is 
  very 
  stout, 
  and 
  has 
  a 
  straight 
  axis. 
  The 
  posterior 
  prolongations 
  of 
  the 
  

   condyles 
  are 
  broken 
  away, 
  but 
  if 
  the 
  external 
  were 
  as 
  small 
  as 
  in 
  Megalosaurus, 
  it 
  was 
  more 
  external, 
  and 
  the 
  poplit- 
  

   eal 
  concavity 
  not 
  so 
  abruptly 
  distinguished 
  from 
  the 
  posterior 
  face 
  of 
  the 
  shaft 
  above. 
  This 
  extremity 
  of 
  the 
  bone 
  

   more 
  nearly 
  resembles 
  that 
  of 
  the 
  Poeeilopleurum 
  bucklandii, 
  described 
  and 
  figured 
  by 
  Deslongchamps. 
  

  

  In 
  my 
  original 
  description 
  (Proc. 
  A. 
  N. 
  Sci., 
  I860) 
  I 
  reversed 
  the 
  position 
  of 
  this 
  bone, 
  I 
  believe 
  incorrectly, 
  

   which 
  has 
  been 
  observed 
  by 
  Leidy. 
  As 
  it 
  stands 
  broken, 
  the 
  distal 
  extremity 
  is 
  almost 
  identical 
  with 
  that 
  of 
  Hadro- 
  

   saurus, 
  and 
  the 
  proximal 
  with 
  the 
  trochanter 
  furnishes 
  a 
  very 
  good 
  basis 
  for 
  condyles 
  like 
  those 
  of 
  Megalosaurus; 
  

   hence 
  the 
  error. 
  

  

  The 
  relative 
  lengths 
  of 
  the 
  femur 
  and 
  humerus 
  of 
  certain 
  genera 
  of 
  this 
  order 
  may 
  be 
  compared 
  as 
  follows: 
  — 
  

  

  Humerus. 
  

  

  Femur. 
  

  

  Proportion, 
  

  

  19 
  

  

  33. 
  

  

  .575 
  

  

  22.5 
  in. 
  

  

  41.5 
  

  

  .54.2 
  

  

  12 
  in. 
  

  

  35.5 
  

  

  .33.8 
  

  

  13 
  

  

  38 
  

  

  

  Iguanodon 
  anglicus, 
  

   Hadrosaurus 
  foulkei, 
  

   Laelaps 
  aquilunguis, 
  

   Poeeilopleurum 
  bucklandii, 
  

  

  left 
  Tibia. 
  — 
  The 
  tibia 
  is 
  more 
  slender 
  than 
  that 
  belonging 
  to 
  Megalosaurus 
  described 
  by 
  Prof. 
  Owen, 
  and 
  the 
  

   distal 
  articular 
  surface, 
  instead 
  of 
  being 
  lozenge- 
  shaped, 
  is 
  cuneiform, 
  the 
  inner 
  wide 
  extremity 
  oval 
  rounded. 
  Inner 
  

   transverse 
  breadth 
  of 
  proximal 
  head 
  one 
  fourth 
  total 
  length. 
  Anterior 
  crest 
  very 
  strong, 
  much 
  incurved, 
  disappear- 
  

   ing 
  at 
  between 
  the 
  proximal 
  fifth 
  and 
  fourth 
  of 
  length; 
  internal 
  ridge 
  on 
  proximal 
  half, 
  strong, 
  but 
  not 
  reaching 
  

  

  