﻿272 
  PALEONTOLOGY 
  OF 
  ELLIN* 
  

  

  Tin- 
  ventral 
  tube, 
  <>f 
  which 
  some 
  traces 
  can 
  be 
  seen 
  an 
  inch 
  above 
  

   the 
  base, 
  appears 
  to 
  have 
  been 
  cylindrical, 
  starting 
  with 
  the 
  two 
  

   long 
  quadrangular 
  anal 
  plates 
  that 
  reel 
  on 
  the 
  posterior 
  Bubradial 
  

   plate, 
  the 
  succeeding 
  platee 
  decreasing 
  apward 
  in 
  sue. 
  

  

  Column 
  at 
  its 
  appi 
  mity 
  ratlin- 
  large, 
  and 
  oompoeed 
  of 
  ex- 
  

  

  tremely 
  short 
  joints, 
  closely 
  ancyhlosed 
  togethi 
  

  

  Position 
  and 
  locality: 
  Upper 
  pah 
  of 
  the 
  bed, 
  one 
  mile 
  1- 
  

  

  Keokuk. 
  

  

  No. 
  202 
  of 
  Mr. 
  L. 
  A. 
  Cox's 
  collection. 
  

  

  PorxBiooBDnjs 
  [owhhsis, 
  Worthen. 
  

  

  i 
  ;■.,.,.,,■.,.■, 
  % 
  1 
  -. 
  W 
  ra 
  i 
  ■ 
  : 
  ■•■■■■•■:■. 
  

  

  Bulletin 
  No. 
  I, 
  of 
  Hi" 
  Illinois 
  Btata 
  Mu-- 
  um 
  of 
  Ratni*! 
  History, 
  P. 
  «• 
  

  

  Body 
  short, 
  about 
  once 
  and 
  a 
  half 
  as 
  wide 
  as 
  high. 
  Basal 
  plates 
  

   small 
  and 
  hidden 
  by 
  the 
  first 
  columnar 
  joints. 
  Bubradials 
  small. 
  

   slightly 
  protuberant 
  at 
  the 
  center 
  and 
  depi 
  al 
  the 
  angles. 
  

  

  Badials 
  twice 
  as 
  wide 
  as 
  Long, 
  pentagonal, 
  depressed 
  on 
  their 
  lower 
  

   lateral 
  borders, 
  with 
  a 
  tolerably 
  well 
  denned 
  suture 
  between 
  them 
  

   and 
  the 
  brachials. 
  

  

  Brachials 
  two, 
  the 
  firs! 
  quadrangular, 
  twist 
  a- 
  wide 
  as 
  long, 
  the 
  

   second 
  pentagonal, 
  giving 
  support 
  on 
  their 
  sloping 
  angles 
  to 
  I 
  

   firs! 
  divisions 
  of 
  the 
  rays, 
  and 
  slightly 
  protuberani 
  at 
  their 
  op] 
  

   angles. 
  

  

  Arm- 
  after 
  the 
  first 
  division 
  ou 
  the 
  second 
  brachial 
  in 
  two 
  of 
  the 
  

  

  rays, 
  the 
  left 
  posterior 
  and 
  righl 
  anterolateral 
  ray- 
  divide 
  again 
  

  

  ,,n 
  the 
  fifth 
  to 
  the 
  seventh 
  plate, 
  beyond 
  which 
  they 
  are 
  simple 
  as 
  

   fur 
  as 
  they 
  have 
  been 
  preserved. 
  On 
  another 
  ray. 
  which 
  may 
  

  

  the 
  anterior 
  one. 
  the 
  first 
  bifurcation 
  take- 
  place 
  apparently 
  on 
  the 
  

  

  fifth 
  brachial, 
  and 
  the 
  second 
  one 
  on 
  the 
  thud 
  plate 
  above, 
  asm 
  

  

  oan 
  be 
  determined 
  from 
  the 
  crushed 
  condition 
  of 
  tins 
  ray. 
  Anal 
  

   plates 
  unknown. 
  

  

  Column 
  round. 
  OOmpoaed 
  of 
  rather 
  thick 
  joints 
  near 
  the 
  ! 
  

  

  ming 
  alt. 
  rnafa 
  ly 
  thinner 
  below 
  

   This 
  species 
  is 
  related 
  to 
  I 
  ' 
  " 
  f 
  White, 
  but 
  dif- 
  

  

  fers 
  from 
  it 
  m 
  the 
  number 
  and 
  mode 
  <-f 
  bifurcation 
  of 
  thi 
  

   and 
  also 
  in 
  the 
  form 
  and 
  proportion 
  of 
  the 
  plan- 
  composing 
  the 
  

  

  body. 
  

  

  turn 
  and 
  fa 
  [Jppar 
  ■bales 
  of 
  the 
  goods 
  bt 
  

  

  l..u 
  Keokuk, 
  towa. 
  

   v, 
  m,-. 
  I 
  . 
  \. 
  Cox's 
  collection. 
  

  

  ; 
  „ 
  !in 
  oi 
  this 
  specimen 
  was 
  not 
  figun 
  d 
  

  

  