﻿32 
  

  

  THE 
  EXTINCT 
  BATRACHIA, 
  REPTILIA 
  

  

  Fie. 
  5. 
  

  

  Fig-. 
  6. 
  

  

  MECISTOPS 
  INTERMEBIUS. 
  

  

  Limbs 
  ambulatory, 
  no 
  third 
  trochanter. 
  

  

  Sacrum 
  of 
  two 
  vertebrae. 
  

  

  No 
  procoracoid 
  or 
  clavicle. 
  

  

  Ribs 
  mostly 
  double-headed. 
  

  

  External 
  nostrils 
  anterior. 
  

  

  Pubes 
  longitudinal, 
  not 
  entering 
  acetabulum 
  ; 
  free 
  distally. 
  

  

  Zygapophyses 
  only 
  ; 
  chevron 
  bones 
  

  

  CROCODILIA. 
  

  

  Limbs 
  ambulatory; 
  a 
  third 
  trochanter 
  on 
  femur. 
  

  

  Sacrum 
  of 
  two 
  or 
  three 
  vertebrae 
  ; 
  acetabulum 
  entire 
  ; 
  pubes 
  united. 
  

  

  Ribs 
  double-headed. 
  

  

  External 
  nostrils 
  posterior. 
  

  

  Zygapophyses 
  only 
  and 
  chevron 
  bones. 
  

  

  THECODONTIA. 
  

   Limbs 
  ambulatory 
  or 
  prehensile. 
  

  

  Ilium 
  horizontal, 
  supporting 
  a 
  long 
  sacrum 
  of 
  five 
  or 
  six 
  vertebrae, 
  the 
  anterior 
  derived 
  

  

  from 
  the 
  lumbar 
  scries. 
  

  

  The 
  acetabulum 
  thrown 
  forwards, 
  and 
  not 
  complete, 
  but 
  perforate. 
  

  

  