﻿24:8 
  THE 
  EXTINCT 
  BATRACHIA, 
  EEPTILIA 
  

  

  habit 
  rivers 
  and 
  lakes. 
  Trionyx, 
  a 
  well-known 
  river 
  type, 
  is 
  represented 
  by 
  three 
  species 
  ; 
  

   none 
  are 
  known 
  to 
  be 
  marine. 
  

  

  There 
  remain 
  the 
  orders 
  Pythonomorpha 
  and 
  Sauropterygia, 
  none 
  of 
  whose 
  members 
  

   exist 
  at 
  the 
  present 
  day. 
  These 
  were 
  probably 
  truly 
  marine, 
  as 
  well 
  as 
  associated 
  with 
  

   the 
  estuary 
  types 
  already 
  enumerated. 
  

  

  It 
  may 
  be 
  asserted 
  that 
  there 
  is 
  no 
  systematic 
  evidence 
  to 
  show 
  that 
  the 
  ancient 
  re- 
  

   presentatives 
  of 
  our 
  fresh-water 
  forms 
  were 
  not 
  marine, 
  and 
  to 
  this 
  a 
  partial 
  assent 
  may 
  

   be 
  given. 
  We 
  may 
  look 
  to 
  some 
  other 
  sources 
  of 
  evidence 
  in 
  explanation 
  of 
  the 
  question. 
  

  

  The 
  most 
  westward 
  division 
  of 
  the 
  Cretaceous, 
  embracing 
  the 
  bed 
  No. 
  1 
  , 
  of 
  Meek 
  and 
  

   Hayden, 
  which 
  contains 
  abundant 
  leaves, 
  etc., 
  of 
  terrestrial 
  plants, 
  may 
  have 
  been 
  more 
  

   entirely 
  fresh 
  than 
  the 
  others, 
  as 
  I 
  have 
  suggested, 
  Proceed. 
  Acad. 
  Natl. 
  Sci., 
  1868, 
  157.* 
  

  

  The 
  second, 
  or 
  Ripley 
  clay, 
  has 
  produced 
  few 
  vertebrate 
  remains, 
  the 
  most 
  important, 
  

   the 
  Hadrosarus 
  foulkei, 
  a 
  terrestrial 
  animal. 
  The 
  molluses 
  are 
  largely 
  marine. 
  

  

  The 
  third 
  series, 
  embracing 
  the 
  lower 
  green-sand 
  bed, 
  contains 
  more 
  numerous 
  verte- 
  

   brates, 
  as 
  Mosasaurus, 
  Thoracosaurus, 
  etc., 
  but, 
  as 
  my 
  friend, 
  Jno. 
  Smock, 
  of 
  the 
  State 
  

   Survey, 
  has 
  observed, 
  almost 
  no 
  tortoises. 
  To 
  this, 
  one 
  exception 
  occurs 
  in 
  the 
  Trionyx 
  

   halophilus, 
  Cope, 
  which 
  is 
  from 
  near 
  the 
  Delaware 
  and 
  Chesapeake 
  Canal, 
  in 
  Delaware, 
  

   from 
  the 
  lower 
  bed. 
  The 
  species 
  which 
  are 
  only 
  known 
  from 
  these 
  two 
  clays 
  and 
  marls, 
  

   are 
  as 
  follows: 
  

  

  From 
  the 
  Clays 
  of 
  No. 
  I. 
  

  

  Plesiosaurus 
  lockwoodii. 
  

  

  Ornithotarsus 
  immanis. 
  

  

  Hadrosaurus 
  foulkei. 
  

   From 
  the 
  Clays 
  and 
  Marl 
  of 
  the 
  first 
  heel. 
  

  

  Elasmosaurus 
  orientalis. 
  

  

  Clidastes 
  iguanavus. 
  

  

  Mosasaurus 
  fulciatus. 
  

  

  Mosasaurus 
  maximus. 
  

  

  Mosasaurus 
  dekayi. 
  

  

  Trionyx 
  halophilus. 
  

   Trionyx 
  priscus. 
  

   Emys 
  sp. 
  

   Beryx 
  insculptus 
  (fish). 
  

  

  From 
  the 
  Rotten 
  Limestone 
  of 
  Alabama. 
  

   Mosasaurus 
  brumbyi. 
  

   Liodon 
  congrops. 
  

   Clidastes 
  propython. 
  

   Clidastes 
  intermedius. 
  

  

  The 
  fourth 
  series, 
  embracing 
  the 
  second 
  green-sand 
  bed, 
  contains 
  the 
  greatest 
  number 
  

   of 
  vertebrate 
  species, 
  distributed 
  as 
  follows 
  : 
  

  

  Sauropterygia, 
  2; 
  Crocodilia, 
  10; 
  Dinosauria, 
  4; 
  Testudinata, 
  22; 
  Pythonomorpha, 
  6. 
  

   The 
  remains 
  of 
  these 
  are 
  all 
  found 
  in 
  the 
  lower 
  division 
  of 
  the 
  green-sand 
  bed, 
  denned 
  

  

  * 
  T. 
  A. 
  Conrad 
  and 
  Prof. 
  Newberry, 
  believe 
  these 
  beds 
  to 
  be 
  Triassic; 
  I 
  have 
  stated 
  it 
  as 
  my 
  belief, 
  that 
  some 
  of 
  

   them 
  are 
  Jurassic. 
  I 
  am 
  confirmed 
  in 
  this 
  opinion 
  by 
  the 
  discovery 
  of 
  a 
  species 
  of 
  Asteracanthus, 
  by 
  Dr. 
  G. 
  J. 
  

   Fisher, 
  of 
  Sing-Sing, 
  a 
  genus 
  known 
  only 
  in 
  the 
  Jurassics 
  of 
  the 
  old 
  world. 
  

  

  