﻿68 
  THE 
  EXTINCT 
  BATRACHIA, 
  REPTILIA 
  

  

  The 
  lumbars 
  grow 
  widest 
  as 
  respect 
  the 
  centrum, 
  to 
  the 
  sacrum. 
  The 
  two 
  sacral 
  vertebrae 
  

   are 
  the 
  broadest 
  and 
  most 
  depressed 
  and 
  their 
  cups 
  and 
  balls 
  are 
  flattened. 
  

  

  The 
  parapophyses 
  rise 
  from 
  the 
  atlas 
  till 
  they 
  stand 
  truncated 
  above 
  by 
  neurapophysial 
  

   suture 
  on 
  the 
  fifth 
  dorsal. 
  On 
  the 
  sixth 
  dorsal 
  they 
  stand 
  just 
  above 
  the 
  suture, 
  and 
  on 
  

   the 
  seventh 
  on 
  a 
  level 
  with 
  anterior 
  zygapophysis 
  (H. 
  brevispinis). 
  Among 
  modern 
  Croc- 
  

   odiles, 
  Caimans 
  and 
  Gavials, 
  Cuvier 
  found 
  hypapophyses 
  on 
  the 
  anterior 
  five 
  or 
  six 
  dorsal 
  

   vertebrae 
  ; 
  on 
  the 
  Holopes 
  and 
  Thoracosaurus 
  these 
  processes 
  are 
  visible 
  on 
  the 
  eighth, 
  

   and 
  probably 
  on 
  the 
  ninth 
  in 
  H. 
  brevispinis 
  Cope. 
  

  

  The 
  teeth 
  in 
  this 
  genus 
  are 
  much 
  curved. 
  They 
  have 
  long 
  conic 
  crowns 
  with 
  minute 
  

   lateral 
  cutting 
  edges 
  and 
  minute 
  striae 
  of 
  the 
  enamel, 
  but 
  no 
  proper 
  ridges 
  as 
  in 
  Hypo- 
  

   saurus. 
  The 
  teeth 
  in 
  T. 
  neocaesariensis 
  are 
  blunter 
  than 
  in 
  the 
  others. 
  In 
  the 
  H. 
  

   glyptodon, 
  the 
  teeth 
  are 
  coarsely 
  fluted, 
  and 
  the 
  surface 
  everywhere, 
  finely 
  and 
  sharply 
  

   striate. 
  

  

  As 
  the 
  vertebrae 
  of 
  the 
  species 
  of 
  this 
  genus 
  are 
  very 
  numerous, 
  and 
  the 
  crania 
  are 
  

   usually 
  much 
  mutilated 
  before 
  coming 
  to 
  the 
  hands 
  of 
  students, 
  I 
  give 
  a 
  synopsis 
  of 
  their 
  

   characters, 
  including 
  those 
  of 
  Thoracosaurus 
  and 
  Bottosaurus. 
  

  

  I. 
  Cervicals 
  with 
  deeply 
  bifid 
  hypapophyses, 
  and 
  transversely 
  oval 
  cup. 
  

   Dorsals 
  with 
  transverse 
  oval 
  cups. 
  

  

  T. 
  NEOCAESARIENSIS. 
  

  

  II. 
  Cervicals 
  with 
  short 
  united 
  transverse 
  hypophyses, 
  slightly 
  bifid 
  posteriorly 
  ; 
  

   anterior 
  extremities 
  more 
  or 
  less 
  quadrate. 
  

  

  Smallest 
  species, 
  vertebrae 
  16 
  lines 
  long 
  (without 
  ball) 
  ; 
  cups 
  of 
  all 
  transverse 
  oval. 
  

  

  H. 
  BREVISPINIS. 
  

  

  Large 
  ; 
  dorsals 
  about 
  third 
  and 
  fifth, 
  with 
  subcordate 
  outline 
  and 
  thin 
  margins 
  ; 
  i. 
  e,, 
  

   widened 
  above, 
  narrowed 
  below, 
  wider 
  than 
  deep 
  ; 
  centra 
  20-25 
  lines 
  ; 
  cervicals 
  with 
  

   subquadrate 
  cup. 
  

  

  H. 
  CORDATUS. 
  

  

  Large, 
  centra 
  20-25 
  lines 
  long 
  ; 
  dorsals 
  about 
  seventh, 
  etc., 
  much 
  compressed 
  ; 
  cups 
  

   deeper 
  than 
  wide, 
  third 
  and 
  fourth 
  regularly 
  round 
  or 
  oval, 
  not 
  cordate, 
  with 
  thick 
  lips 
  ; 
  

   cups 
  of 
  cervicals 
  round 
  or 
  transverse 
  oval. 
  

  

  H. 
  OBSCURUS. 
  

  

  " 
  III. 
  Posterior 
  cervicals 
  with 
  hypapophyses 
  scarcely 
  traceable, 
  and 
  well 
  separated. 
  

   Large 
  species 
  ; 
  dorsals 
  near 
  seventh, 
  with 
  transverse 
  oval 
  cup, 
  with 
  thick 
  margins 
  ; 
  

   cups 
  of 
  cervicals 
  subquadrate, 
  bodies 
  little 
  keeled 
  below 
  ; 
  centra 
  20-25 
  lines 
  long. 
  

  

  H. 
  TENEBROSUS. 
  

  

  