﻿l'ALiEONTOLnc.Y 
  OF 
  tLLINO] 
  

  

  the 
  spine. 
  These 
  nodose 
  spinule- 
  continue 
  down 
  over 
  the 
  middle 
  

   portion 
  of 
  the 
  Bpine, 
  but 
  they 
  are 
  Bmaller 
  and 
  less 
  numerous 
  than 
  

   on 
  the 
  elavate 
  portion 
  ahovt-. 
  The 
  Lower 
  part 
  <>f 
  the 
  long 
  spines 
  

   are 
  nearly 
  or 
  quite 
  destitute 
  of 
  spinules, 
  hut 
  on 
  the 
  short, 
  r 
  ones 
  

   they 
  continue 
  marly 
  to 
  the 
  hasal 
  ring. 
  This 
  ring 
  is 
  marly 
  twice 
  

   the 
  diameter 
  of 
  the 
  articulating 
  extremity, 
  and 
  smooth. 
  

  

  Interamhulacral 
  platefl 
  In 
  xagonal, 
  with 
  a 
  nodose 
  rim 
  around 
  their 
  

   margins, 
  and 
  there 
  are 
  indications 
  of 
  low 
  granules 
  scattered 
  spar- 
  

   ingly 
  over 
  the 
  outer 
  surface 
  of 
  some 
  of 
  them, 
  hut 
  they 
  are 
  highly 
  

   silicified, 
  and 
  their 
  external 
  markings 
  thereby 
  obscured. 
  

  

  Central 
  tuhercle 
  strongly 
  elevated, 
  papilliform, 
  with 
  a 
  rather 
  deep 
  

   space 
  between 
  it 
  and 
  the 
  annnlation, 
  the 
  latter 
  forming 
  a 
  distinct 
  

   and 
  Blightly 
  projeoting 
  rim 
  for 
  its 
  support. 
  

  

  This 
  species 
  may 
  le 
  readily 
  distinguished 
  from 
  other 
  Coal 
  I 
  

   species 
  by 
  the 
  Bpino-clavate 
  character 
  of 
  its 
  spines. 
  

  

  Position 
  niul 
  localities: 
  Middle 
  and 
  Lower 
  Coal 
  Measui 
  - 
  Clair 
  

   and 
  Marshall 
  counties, 
  Illinois. 
  

  

  No. 
  "J, 
  -101 
  Illinois 
  State 
  collection. 
  

  

  Allt'ILKOCIDAkls 
  [lLINOIBNSIS, 
  S|). 
  nov. 
  

   PI. 
  XXXI. 
  Fi 
  K 
  . 
  1. 
  a.b. 
  

  

  Primary 
  spines 
  rather 
  stout, 
  cylindrical, 
  tap. 
  rin. 
  radually 
  

  

  above 
  the 
  articulating 
  ring 
  to 
  their 
  extremities. 
  Articulating 
  ring 
  

   subangular, 
  and 
  from 
  thi> 
  the 
  spines 
  oontrael 
  rapidly 
  to 
  the 
  articu- 
  

   lating 
  extremity. 
  .Iu>t 
  above 
  the 
  articulating 
  ring 
  the 
  Bpines 
  arc 
  

   slightly 
  curved, 
  and 
  above 
  the 
  curvature 
  they 
  are 
  studded 
  with 
  short 
  

  

  sharp 
  Bpinules 
  that 
  an 
  directed 
  outward 
  and 
  >liL'litlv 
  upward 
  

  

  towards 
  the 
  extremity 
  of 
  the 
  Bpine. 
  The 
  articulating 
  end 
  is 
  perfo- 
  

   rated 
  by 
  a 
  round 
  aperture, 
  which 
  extends 
  about 
  to 
  the 
  articulating 
  

  

  The 
  onlj 
  specimens 
  of 
  this 
  species 
  yet 
  obtained 
  oonsist 
  of 
  pri- 
  

   mar] 
  . 
  and 
  Borne 
  fragments 
  of 
  the 
  inter-ambulacra] 
  pi 
  

  

  the 
  latter 
  tod 
  imperfect 
  for 
  an 
  aocui 
  tion. 
  

  

  / 
  ition 
  ,vul 
  locality: 
  Prom 
  the 
  black 
  beds 
  of 
  the 
  Bt. 
  Louis 
  lime- 
  

   stone, 
  neai 
  the 
  Illinois 
  Furnace, 
  Bardin 
  county, 
  Dlini 
  

  

  No. 
  -i. 
  it:, 
  of 
  :i,, 
  lih, 
  o 
  si 
  •. 
  coUecti< 
  

  

  