﻿AND 
  AYES 
  OF 
  NORTH 
  AMERICA. 
  122-C 
  

  

  acters. 
  The 
  proximal 
  extremity 
  resembles 
  that 
  of 
  the 
  Crocodilia, 
  while 
  the 
  distal 
  is 
  truly 
  

   Dinosaurian, 
  approaching 
  Megalosaurus. 
  There 
  is 
  no 
  distinct 
  head, 
  the 
  whole 
  extremity 
  

   is 
  compressed, 
  and 
  the 
  extremital 
  surface 
  concave 
  in 
  its 
  long 
  axis. 
  It 
  overhangs 
  the 
  shaft 
  

   on 
  the 
  inner 
  side 
  and 
  forms 
  a 
  knob 
  which 
  is 
  decurved, 
  and 
  contracts 
  below 
  abruptly 
  to 
  

   the 
  shaft. 
  The 
  external 
  margin 
  is 
  a 
  subacute 
  ridge 
  ; 
  the 
  small 
  trochanter 
  is 
  represented 
  

   by 
  a 
  short 
  ridge 
  which 
  is 
  but 
  little 
  denned 
  on 
  the 
  inner 
  side, 
  and 
  which 
  sinks 
  to 
  the 
  gen- 
  

   eral 
  level 
  some 
  distance 
  below 
  the 
  head. 
  The 
  compression 
  of 
  the 
  shaft 
  changes 
  to 
  a 
  

   sub-cylindric 
  form, 
  and 
  just 
  above 
  this 
  point 
  the 
  large 
  third 
  trochanter 
  projects. 
  It 
  is 
  

   short 
  ; 
  inside 
  of 
  it 
  a 
  large 
  rugose 
  surface 
  indicates 
  the 
  insertion 
  of 
  a 
  powerful 
  muscle. 
  

   Near 
  the 
  distal 
  extremity 
  the 
  shaft 
  is 
  compressed 
  transversely. 
  The 
  articular 
  face 
  of 
  the 
  

   condyles 
  is 
  rather 
  flat. 
  The 
  outer 
  has 
  the 
  least 
  posterior 
  production, 
  and 
  has 
  a 
  contin- 
  

   uous 
  exterior 
  face. 
  The 
  inner 
  is 
  divided 
  exteriorly, 
  near 
  the 
  posterior 
  extremity, 
  by 
  a 
  deep 
  

   groove, 
  which 
  is 
  continued 
  obliquely 
  forward 
  and 
  inward 
  on 
  the 
  articular 
  face. 
  The 
  

   anterior 
  part 
  of 
  this 
  condyle 
  is 
  strongly 
  convex. 
  The 
  posterior 
  is 
  narrow 
  and 
  turned 
  in- 
  

   wards 
  and 
  backwards 
  to 
  a 
  sharp 
  edge. 
  This 
  portion 
  is 
  outlined 
  by 
  the 
  above 
  mentioned 
  

   groove, 
  and 
  forms 
  a 
  narrow 
  ovate 
  in 
  section. 
  The 
  popliteal 
  groove 
  is 
  quite 
  deep, 
  and 
  the 
  

   trochlear 
  scarcely 
  marked. 
  

  

  The 
  tibia 
  and 
  fibula 
  are 
  broken. 
  Of 
  the 
  first, 
  a 
  piece 
  of 
  the 
  proximal 
  portion 
  alone 
  

   remains 
  ; 
  of 
  the 
  latter, 
  a 
  piece 
  is 
  broken 
  from 
  the 
  middle 
  of 
  the 
  shaft. 
  The 
  head 
  of 
  the 
  

   tibia 
  is 
  flattened 
  by 
  pressure. 
  The 
  spine 
  or 
  crest 
  is 
  very 
  prominent, 
  but 
  not 
  so 
  much 
  so 
  

   as 
  in 
  Lselaps, 
  and 
  is 
  much 
  curved 
  outwards. 
  The 
  posterior 
  angle 
  of 
  the 
  proximal 
  extremity 
  

   is 
  prominent, 
  and 
  the 
  prominence 
  to 
  which 
  the 
  fibula 
  is 
  applied 
  marks 
  the 
  anterior 
  third 
  

   of 
  the 
  long 
  diameter 
  of 
  the 
  head 
  in 
  its 
  present 
  condition. 
  The 
  anterior 
  crest 
  gradually 
  

   sinks 
  to 
  the 
  shaft. 
  The 
  greater 
  part 
  of 
  the 
  latter 
  is 
  flat, 
  as 
  an 
  impression 
  in 
  the 
  matrix 
  

   indicates. 
  The 
  fibula 
  is 
  slender 
  and 
  oval 
  in 
  section, 
  with 
  very 
  thin 
  walls. 
  At 
  the 
  distal 
  

   extremity 
  it 
  expands 
  slightly 
  ; 
  the 
  articular 
  face 
  is 
  plane 
  transversely, 
  and 
  moderately 
  con- 
  

   vex 
  antero-posteriorly. 
  Proximally 
  the 
  shaft 
  expands 
  in 
  the 
  direction 
  opposite 
  to 
  its 
  

   compression, 
  giving 
  the 
  head 
  a 
  nearly 
  equal 
  extent 
  in 
  both 
  directions. 
  The 
  articular 
  

   surface 
  is 
  directed 
  obliquely 
  downwards 
  to 
  the 
  tibia, 
  and 
  is 
  more 
  or 
  less 
  grooved 
  ; 
  a 
  strong 
  

   rabbet 
  extends 
  round 
  its 
  posterior 
  angle. 
  

  

  The 
  foot 
  is 
  in 
  relation 
  to 
  the 
  extremity 
  of 
  the 
  leg, 
  in 
  a 
  strongly 
  flexed 
  position. 
  The 
  

   tarsal 
  and 
  metatarsal 
  elements 
  were 
  somewhat 
  separated 
  by 
  the 
  strain, 
  though 
  in 
  nearly 
  

   normal 
  position. 
  

  

  The 
  cuboid 
  bone 
  alone 
  remains 
  of 
  these. 
  It 
  is 
  closely 
  approximated 
  to 
  the 
  fibula 
  with 
  

   a 
  small 
  interval 
  occupied 
  by 
  matrix 
  between. 
  The 
  form 
  is 
  somewhat 
  like 
  that 
  in 
  the 
  

   genus 
  Alligator, 
  and 
  it 
  bears 
  a 
  similar 
  relative 
  size 
  to 
  the 
  adjacent 
  elements. 
  It 
  is 
  a 
  sub- 
  

   triangular 
  piece 
  with 
  concave 
  sides 
  ; 
  the 
  posterior 
  angle, 
  as 
  it 
  were, 
  pinched. 
  One 
  lateral 
  

  

  