﻿154 
  

  

  THE 
  EXTINCT 
  BATRACHIA, 
  EEPTILIA 
  

  

  The 
  ossification 
  of 
  the 
  disc 
  is 
  perhaps 
  more 
  extensive 
  than 
  in 
  C. 
  mydas, 
  if 
  the 
  small 
  size 
  of 
  the 
  extremities 
  of 
  

   the 
  ribs 
  be 
  indication. 
  They 
  are 
  very 
  flat 
  in 
  both 
  directions. 
  The 
  surface 
  is 
  smooth, 
  or 
  with 
  only 
  the 
  vascular 
  

   grooves 
  found 
  in 
  the 
  species 
  of 
  the 
  family 
  generally. 
  A 
  nuchal 
  or 
  marginal 
  vertebral 
  is 
  partially 
  preserved, 
  having 
  

   lost 
  the 
  posterior 
  portion. 
  The 
  margin 
  is 
  heavy, 
  thinner 
  than 
  as 
  usual 
  medially, 
  and 
  with 
  a 
  little 
  irregularity 
  where 
  

   the 
  dermal 
  scutum 
  crosses. 
  The 
  suture 
  with 
  the 
  first 
  marginal 
  is 
  nearly 
  straight, 
  except 
  that 
  the 
  latter 
  sends 
  a 
  flat 
  

   process 
  a 
  considerable 
  distance 
  over 
  the 
  posterior 
  face 
  of 
  the 
  former. 
  

  

  The 
  right 
  scapula 
  and 
  part 
  of 
  the 
  procoracoid 
  are 
  preserved. 
  These 
  have 
  the 
  extensive 
  union 
  characteristic 
  of 
  

   Chelone, 
  and 
  the 
  short 
  coracoid 
  suture. 
  The 
  scapula 
  is 
  flattened 
  so 
  as 
  to 
  be 
  antero-posterior 
  above, 
  transverse 
  below. 
  

   The 
  procoracoid 
  is 
  strongly 
  compressed 
  to 
  a 
  vertical 
  section. 
  The 
  head 
  and 
  great 
  trochanter 
  of 
  the 
  femur 
  are 
  pre- 
  

   served. 
  These 
  also 
  present 
  the 
  characters 
  of 
  Chelone. 
  The 
  little 
  trochanter 
  is 
  on 
  the 
  shaft 
  some 
  distance 
  below 
  the 
  

   head. 
  All 
  but 
  its 
  base 
  is 
  lost. 
  The 
  great 
  trochanter 
  is 
  higher 
  than 
  the 
  head, 
  and 
  is 
  a 
  plane 
  at 
  right 
  angles 
  to 
  the 
  

   plane 
  of 
  the 
  latter. 
  Its 
  extremity 
  is 
  conic, 
  and 
  its 
  connecting 
  portion 
  contracted 
  and 
  descending 
  below 
  the 
  line 
  of 
  

  

  the 
  head. 
  

  

  Lines. 
  

  

  "Width 
  of 
  costal 
  bone, 
  39.5 
  

  

  Thickness 
  " 
  at 
  suture, 
  6. 
  

  

  " 
  of 
  nuchal 
  bone 
  at 
  marginal 
  suture, 
  9. 
  

  

  Length 
  neck 
  scapulo-procoracoid, 
  42. 
  

  

  Width 
  " 
  " 
  18. 
  

  

  Length 
  coracoid 
  suture, 
  18. 
  

  

  Depth 
  procoracoid 
  at 
  middle, 
  16. 
  

  

  38. 
  

  

  Length 
  scapula 
  to 
  infer, 
  side, 
  

  

  20. 
  

  

  22.8 
  

  

  45.3 
  

  

  Width 
  " 
  extremity, 
  

  

  Transverse 
  diameter 
  shaft 
  femur, 
  

  

  Diameter 
  shaft 
  and 
  great 
  trochanter, 
  

   The 
  accompanying 
  cuts 
  show 
  the 
  forms 
  of 
  the 
  head 
  of 
  the 
  femur 
  and 
  of 
  the 
  scapula. 
  

  

  Another 
  specimen 
  in 
  the 
  museum 
  of 
  the 
  Academy, 
  from 
  the 
  same 
  locality, 
  exhibits 
  the 
  characters 
  of 
  four 
  margi- 
  

   nal 
  bones 
  and 
  a 
  fragment 
  of 
  one 
  of 
  the 
  hyosternals. 
  In 
  general 
  characters 
  the 
  middle 
  and 
  posterior 
  of 
  the 
  former 
  are 
  

  

  Fig. 
  41. 
  

  

  Fig. 
  40. 
  

  

  c; 
  

  

  like 
  those 
  of 
  Propleura; 
  the 
  anterior 
  presents 
  the 
  characteristic 
  slenderness 
  seen 
  in 
  Cheloue. 
  One 
  end 
  of 
  the 
  latter 
  

   is 
  broken; 
  the 
  remainder 
  measures 
  four 
  inches 
  in 
  length, 
  22.5 
  lines 
  in 
  width, 
  and 
  only 
  10.5 
  lines 
  in 
  depth 
  medially, 
  

   being 
  flat 
  and 
  thin. 
  The 
  outer 
  margin 
  is 
  flat 
  and 
  entire. 
  The 
  inner 
  presents 
  two 
  shallow 
  pits 
  at 
  its 
  posterior 
  part, 
  

   close 
  together, 
  the 
  hinder 
  partly 
  on 
  the 
  suture 
  with 
  the 
  adjoining 
  marginal, 
  and 
  directed 
  a 
  little 
  forwards; 
  the 
  an- 
  

   terior 
  directed 
  backwards. 
  As 
  this 
  is 
  probably 
  the 
  anterior 
  rib-bearing, 
  or 
  third 
  marginal, 
  it 
  looks 
  probable 
  that 
  

  

  