﻿30 
  THE 
  EXTINCT 
  BATRACHIA, 
  REPTILIA 
  

  

  EOSAURUS, 
  Marsh* 
  

  

  This 
  genus, 
  as 
  suggested 
  by 
  Huxley, 
  may 
  be 
  the 
  type 
  of 
  a 
  peculiar 
  division 
  of 
  the 
  

   Batrachia. 
  There 
  appears 
  to 
  be 
  some 
  probability 
  of 
  this 
  being 
  found 
  to 
  be 
  the 
  case, 
  though 
  

   present 
  evidence 
  is 
  in 
  favor 
  of 
  Prof. 
  Marsh's 
  location 
  here. 
  

  

  EOSAURUS 
  ACADIANUS, 
  Marsh. 
  

   Amer. 
  Jour. 
  Science, 
  xxxiv. 
  1862, 
  1 
  Tab. 
  I, 
  II. 
  

  

  Coal 
  measures 
  : 
  Joggins 
  of 
  Nova 
  Scotia. 
  

  

  ARCIIOSAITRIA. 
  

  

  This 
  great 
  order 
  of 
  Reptilia 
  corresponds 
  with 
  the 
  Monimostylica 
  of 
  Miiller, 
  without 
  

   the 
  Testudinata. 
  The 
  latter 
  differ 
  too 
  much 
  in 
  the 
  vertebral 
  and 
  sternal 
  structure 
  to 
  be 
  

   retained 
  in 
  it. 
  

  

  The 
  important 
  feature 
  which 
  characterizes 
  the 
  order, 
  the 
  close 
  sutural 
  attachment 
  of 
  

   the 
  quadrate 
  bone, 
  may 
  be 
  readily 
  understood 
  by 
  comparison 
  of 
  the 
  accompanying 
  figures 
  

   of 
  Nothosaurus 
  from 
  the 
  Muschelkalk 
  of 
  Germany, 
  and 
  Mecistops 
  intermedins 
  Graves,"}" 
  

   recent, 
  from 
  the 
  Orinoco, 
  with 
  the 
  plate 
  of 
  Clidastes 
  propython, 
  at 
  the 
  end 
  of 
  the 
  volume. 
  

  

  The 
  order 
  embraces 
  that 
  large 
  series 
  of 
  forms 
  which 
  seem 
  to 
  be 
  equidistant 
  between 
  

   all 
  the 
  extremes 
  of 
  the 
  Reptilian 
  type. 
  It 
  therefore 
  is 
  not 
  a 
  strictly 
  homogenous 
  group 
  ; 
  

   yet 
  its 
  subdivisions 
  do 
  not 
  appear, 
  with 
  present 
  knowledge, 
  to 
  be 
  sufficiently 
  marked, 
  to 
  

   render 
  it 
  proper 
  to 
  esteem 
  them 
  of 
  equal 
  value 
  with 
  the 
  other 
  orders 
  here 
  enumerated. 
  

   This 
  is 
  a 
  usual 
  difficulty 
  of 
  classification 
  ; 
  we 
  express 
  it, 
  and 
  do 
  not 
  remove 
  it, 
  by 
  admitting 
  

   the 
  existence 
  of 
  a 
  protean 
  type 
  in 
  a 
  genus 
  of 
  species, 
  a 
  family 
  of 
  genera, 
  a 
  class 
  of 
  orders, 
  

   etc., 
  etc. 
  The 
  suborders 
  are 
  as 
  follows 
  : 
  

  

  Limbs 
  without 
  flexible 
  articulation 
  ; 
  natatory 
  ; 
  no 
  femoral 
  trochanters 
  ; 
  no 
  sacrum. 
  

   A 
  procoracoid 
  united 
  with 
  scapula 
  ; 
  a 
  distinct 
  episternum. 
  

   Ribs 
  single 
  headed. 
  

  

  * 
  The 
  following 
  species 
  have 
  been 
  described 
  by 
  Leidy, 
  who 
  refers 
  them 
  to 
  Eeptilia 
  with 
  doubt, 
  and 
  says 
  they 
  may 
  

   be 
  fishes. 
  As 
  this 
  point 
  remains 
  undecided, 
  I 
  can 
  only 
  allude 
  to 
  them 
  here. 
  

  

  CYMBOSPONDYLUS, 
  Leidy. 
  

   Proceedings 
  Acad. 
  Nat. 
  Sciences, 
  Philada., 
  1858. 
  — 
  178. 
  

  

  CYMBOSPONDYLUS 
  PISCOSUS, 
  Leidy, 
  I. 
  c. 
  

   ? 
  Triassic 
  of 
  Humbuldt 
  Co., 
  and 
  of 
  the 
  Toiyabe 
  Range, 
  Nevada. 
  

  

  CYMBOSPONDYLUS 
  PETRINUS, 
  Leidy, 
  I. 
  c. 
  

   ? 
  Triassic 
  ; 
  Humboldt, 
  Nevada. 
  

  

  f 
  This 
  cut 
  is 
  taken 
  from 
  the 
  type 
  specimen 
  of 
  Mecistops 
  bathryhynchus, 
  in 
  Mus. 
  Academy. 
  The 
  Nothosaurus 
  is 
  

   the 
  N. 
  andriani 
  or 
  a 
  nearly 
  allied 
  species. 
  I 
  am 
  not 
  quite 
  positive 
  that 
  the 
  number 
  of 
  alveoli 
  on 
  the 
  maxillary 
  bone 
  

   is 
  exactly 
  correct. 
  

  

  