﻿134: 
  

  

  THE 
  EXTINCT 
  BATRACHIA, 
  REPTILIA 
  

  

  served. 
  The 
  outlines 
  of 
  the 
  episterna 
  are 
  not 
  entirely 
  demonstrable, 
  

   that 
  of 
  the 
  carapace 
  preceding, 
  but 
  is 
  a 
  little 
  too 
  large. 
  

  

  The 
  scale 
  is 
  near 
  

  

  Fiff. 
  39. 
  

  

  OSTEOPYGIS 
  PLATTLOMUS 
  plastl'On. 
  

  

  Dermal 
  sutures 
  are 
  visible 
  in 
  the 
  two 
  species 
  whose 
  sterna 
  we 
  have. 
  Abdominal 
  and 
  

   inguinal 
  plates 
  can 
  be 
  demonstrated; 
  the 
  anterior 
  are 
  not 
  distinguishable. 
  If 
  anal 
  scuta 
  

   exist, 
  they 
  must 
  be 
  very 
  small, 
  but 
  they 
  are 
  probably 
  absent 
  as 
  in 
  Chelydra. 
  

  

  Some 
  of 
  the 
  Eocene 
  Chelones 
  have 
  the 
  posterior 
  vertebral 
  plates 
  more 
  dilated 
  than 
  in 
  

   the 
  recent 
  species, 
  but 
  they 
  all 
  present 
  the 
  penultimate 
  marginals 
  supported 
  by 
  a 
  distinct 
  

   pair 
  of 
  ribs, 
  and 
  the 
  anterior 
  marginals 
  separate 
  from 
  the 
  disc, 
  and 
  without 
  rib. 
  

  

  The 
  femur 
  of 
  a 
  presumed 
  species 
  of 
  the 
  genus 
  is 
  more 
  slender 
  than 
  in 
  the 
  Chelones, 
  

   but 
  resembles 
  closely 
  that 
  of 
  Trionyx, 
  while 
  two 
  phalanges 
  of 
  the 
  same 
  are 
  peculiar 
  in 
  

   their 
  stout 
  base 
  and 
  subterminal 
  constriction. 
  They 
  arc 
  however 
  flattened 
  and 
  have 
  

   transverse 
  distal 
  condyles, 
  being 
  thus 
  rather 
  adapted 
  for 
  paddles 
  than 
  for 
  progression, 
  

   thus 
  showing 
  the 
  genus 
  to 
  have 
  been 
  truly 
  aquatic. 
  

  

  There 
  appear 
  to 
  be 
  remains 
  of 
  three 
  species 
  in 
  our 
  collections 
  distinguished 
  as 
  follows: 
  

  

  