﻿H. 
  G. 
  SEELEY 
  ON 
  NEUSTICOSAUEUS 
  PTJSILLUS. 
  365 
  

  

  proximal 
  end 
  is 
  more 
  than 
  3 
  mm. 
  wide 
  ; 
  the 
  distal 
  end 
  is 
  fully 
  2 
  mm. 
  

   wide. 
  As 
  the 
  specimen 
  lies, 
  the 
  head 
  of 
  the 
  fibula 
  extends 
  in 
  front 
  

   of 
  the 
  tibia. 
  The 
  fibula 
  is 
  a 
  characteristic 
  bone, 
  with 
  the 
  external 
  

   margin 
  straight 
  and 
  the 
  internal 
  margin 
  concave, 
  so 
  that 
  the 
  bone 
  

   is 
  constricted 
  in 
  the 
  middle 
  and 
  expanded 
  at 
  the 
  two 
  ends. 
  

  

  There 
  are 
  only 
  two 
  tarsal 
  bones 
  — 
  first, 
  a 
  large 
  transversely 
  ovate 
  

   tarsal 
  placed 
  between 
  the 
  tibia 
  and 
  fibula, 
  and 
  a 
  similar 
  smaller 
  

   one 
  adjacent 
  to 
  it, 
  and 
  below 
  the 
  fibula. 
  These 
  bones 
  differ 
  in 
  

   proportions 
  somewhat 
  in 
  the 
  two 
  specimens, 
  but 
  have 
  a 
  close 
  general 
  

   resemblance 
  to 
  the 
  tarsals 
  of 
  Plesiosaurus, 
  in 
  having 
  the 
  lateral 
  

   surfaces 
  concave, 
  with 
  an 
  elevated 
  margin 
  round 
  the 
  articular 
  edge. 
  

   The 
  transverse 
  measurement 
  of 
  the 
  large 
  tarsal 
  is 
  4 
  mm. 
  

  

  The 
  metatarsal 
  bones 
  and 
  phalanges 
  of 
  the 
  hind 
  limb, 
  like 
  the 
  

   corresponding 
  bones 
  of 
  the 
  fore 
  limb, 
  in 
  the 
  larger 
  specimen, 
  are 
  

   badly 
  preserved. 
  The 
  foot 
  was 
  short 
  ; 
  but 
  there 
  is 
  no 
  certain 
  evi- 
  

   dence 
  whether 
  it 
  included 
  four 
  or 
  five 
  digits. 
  Besides 
  the 
  meta- 
  

   tarsal 
  there 
  may 
  not 
  have 
  been 
  more 
  than 
  two 
  phalanges 
  in 
  each 
  

   digit, 
  though 
  the 
  number 
  probably 
  varied 
  and 
  augmented. 
  

  

  The 
  metatarsals 
  are 
  compressed 
  from 
  side 
  to 
  side, 
  and 
  somewhat 
  

   enlarged 
  at 
  both 
  ends 
  ; 
  in 
  the 
  larger 
  specimen 
  the 
  first 
  is 
  6 
  mm. 
  

   long. 
  Three 
  terminal 
  phalanges 
  are 
  preserved 
  : 
  they 
  are 
  claws 
  of 
  

   the 
  Lizard 
  pattern, 
  relatively 
  long, 
  compressed 
  from 
  side 
  to 
  side, 
  

   well 
  hooked, 
  and 
  quite 
  unlike 
  the 
  small 
  terminal 
  conical 
  bones 
  in 
  

   the 
  fore 
  limb. 
  

  

  In 
  the 
  smaller 
  specimen 
  the 
  metatarsal 
  bones 
  are 
  better 
  preserved. 
  

   There 
  are 
  four 
  bones 
  placed 
  side 
  by 
  side, 
  and 
  the 
  fractured 
  proxi- 
  

   mal 
  end 
  of 
  a 
  fifth. 
  There 
  is 
  no 
  divergence 
  between 
  the 
  bones, 
  

   which 
  increase 
  slightly 
  in 
  length 
  from 
  the 
  first 
  to 
  the 
  fourth. 
  The 
  

   transverse 
  measurement 
  over 
  these 
  four 
  bones, 
  as 
  preserved, 
  is 
  6 
  mm. 
  ; 
  

   the 
  length 
  of 
  the 
  longest 
  is 
  somewhat 
  more. 
  Only 
  one 
  or 
  two 
  

   fragments 
  of 
  phalanges 
  are 
  preserved, 
  but 
  too 
  imperfect 
  for 
  mea- 
  

   surement. 
  

  

  The 
  point 
  of 
  greatest 
  interest 
  in 
  this 
  animal 
  is 
  probably 
  to 
  be 
  

   found 
  in 
  the 
  diversity 
  of 
  type 
  exhibited 
  by 
  the 
  fore 
  and 
  hind 
  

   limbs. 
  I 
  am 
  disposed 
  to 
  regard 
  the 
  femur 
  as 
  best 
  comparable 
  

   to 
  that 
  of 
  the 
  Triassic 
  Crocodilia, 
  in 
  which 
  the 
  bone 
  is 
  straighter 
  

   than 
  in 
  existing 
  types, 
  and 
  more 
  widened 
  at 
  the 
  proximal 
  end. 
  

   The 
  divergence, 
  however, 
  is 
  so 
  great 
  that 
  intervening 
  types 
  would 
  

   be 
  required 
  to 
  justify 
  a 
  detailed 
  comparison 
  ; 
  and 
  in 
  this 
  matter 
  

   Noihosaurus 
  gives 
  but 
  little 
  help. 
  The 
  remarkable 
  compressed 
  claws 
  

   are 
  not 
  crocodilian, 
  but 
  suggest 
  certain 
  Lizards 
  and 
  various 
  extinct 
  

   animals. 
  

  

  Conclusion. 
  

  

  In 
  endeavouring 
  to 
  estimate 
  the 
  value 
  of 
  the 
  various 
  resemblances 
  

   to 
  Crocodiles 
  which 
  I 
  have 
  attempted 
  to 
  indicate, 
  it 
  must 
  be 
  remem- 
  

   bered 
  that 
  in 
  discussing 
  an 
  animal 
  which 
  lived 
  in 
  the 
  beginning 
  of 
  

   the 
  Secondary 
  period, 
  comparison 
  has 
  had 
  to 
  be 
  made 
  with 
  a 
  type 
  

   which 
  still 
  exists, 
  and 
  which, 
  therefore, 
  can 
  scarcely 
  give 
  much 
  clue 
  

   to 
  the 
  actual 
  modifications 
  which 
  its 
  ancestral 
  forms 
  presented 
  in 
  

   Triassic 
  times. 
  But 
  as 
  the 
  Crocodiles 
  are 
  traced 
  back 
  through 
  the 
  

  

  