﻿PLATE 
  XXV 
  

  

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  .►.••• 
  

  

  Gltmmatacanthus 
  budis, 
  St. 
  and 
  W 
  

  

  Fig. 
  1 
  a. 
  View 
  of 
  fragment 
  of 
  spine 
  from 
  the 
  right 
  side, 
  outline 
  partially 
  restored: 
  

  

  1 
  b, 
  do., 
  from 
  the 
  anterior 
  border; 
  1 
  r, 
  do., 
  transverse 
  section: 
  Keokuk; 
  

   Keokuk, 
  Iowa. 
  Mr. 
  Cox. 
  

  

  Gltmmatacantius 
  petrodoides, 
  St. 
  J. 
  and 
  W 
  250 
  

  

  Fig. 
  2 
  a. 
  View 
  of 
  fragment 
  of 
  spine, 
  showing 
  part 
  of 
  lateral 
  surface 
  tub<-rculation; 
  

  

  2 
  h, 
  do., 
  restored 
  outline 
  of 
  transverse 
  section; 
  2 
  c, 
  do., 
  enlargement, 
  

   showing 
  radlately-soolptored 
  tubercles, 
  as 
  seen 
  in 
  profile. 
  Chester; 
  

   Chester, 
  Illinois. 
  Dr. 
  Hambach. 
  

  

  Obacanthus 
  bectus, 
  St. 
  J. 
  and 
  W 
  

  

  Fig. 
  3n. 
  View 
  of 
  fragment 
  of 
  spine, 
  showing 
  portion 
  oflbe 
  posterior 
  - 
  border; 
  3 
  b. 
  

   do., 
  from 
  the 
  right 
  (?) 
  side; 
  3c, 
  do., 
  in 
  transverse 
  section, 
  restored. 
  

   Chester; 
  Chester, 
  Illinois. 
  Dr. 
  Hambach. 
  

  

  Uatacantfu-s 
  f 
  necis, 
  St. 
  J. 
  and 
  W 
  

  

  Fig. 
  4 
  a. 
  View 
  of 
  spine 
  from 
  the 
  left 
  side, 
  base 
  restored 
  in 
  outline; 
  4 
  b, 
  do., 
  transverse 
  

   sections 
  n>-ar 
  tip 
  and 
  at 
  middle, 
  the 
  latter 
  crushed 
  In 
  over 
  the 
  pulp 
  

   cavity, 
  with 
  a 
  restored 
  section. 
  Keokuk; 
  Keokuk, 
  Iowa. 
  Mr. 
  Cox. 
  

  

  