﻿PLATE 
  XXIV, 
  

  

  PAGE. 
  

  

  

  

  Shumard 
  

  

  (^TEN-ACANTHUS 
  GBACILLIMl'S. 
  N. 
  nild 
  W 
  

  

  Fig. 
  1 
  a. 
  Side 
  view 
  of 
  a 
  nearly 
  entire 
  dorsal 
  spine. 
  St. 
  Louis 
  limestone; 
  

   collection 
  of 
  Washington 
  University. 
  St. 
  Louis, 
  Missouri. 
  

  

  OBACANTH 
  18 
  VETU6TUS, 
  Li 
  -id 
  V 
  

  

  Fig. 
  2 
  a. 
  View 
  of 
  right 
  side 
  of 
  spine; 
  2 
  l>, 
  c. 
  do., 
  transverse 
  sections 
  toward 
  tip 
  and 
  

   near 
  middle, 
  showing 
  thickness 
  of 
  the 
  walls 
  inclosing 
  pulp 
  cavity: 
  - 
  

   do., 
  enlargement 
  of 
  tubercle. 
  St. 
  Louis 
  limestone, 
  St. 
  Louis. 
  Missouri. 
  

   Museum 
  Washington 
  University. 
  

  

  ACONDYLACANTHl'S' 
  MlDOI 
  AXIS, 
  St. 
  J. 
  and 
  W 
  

  

  Fig. 
  3 
  a. 
  View 
  of 
  fragment, 
  showing 
  a 
  strip 
  of 
  the 
  right 
  side 
  near 
  the 
  postero-ln 
  - 
  ' 
  

  

  border 
  with 
  the 
  longitudinal 
  noarc, 
  '. 
  thi 
  ilde 
  em- 
  

  

  bedded 
  in 
  the 
  limestone 
  matrix, 
  will 
  I 
  BWJ 
  

  

  3 
  '/, 
  do., 
  transverse 
  section 
  of 
  spine. 
  Upper 
  Ooal 
  Meat 
  k 
  creek, 
  

  

  near 
  Manhattap, 
  Kmisi-. 
  Mr. 
  St. 
  John. 
  

  

  GTBAGAHTHUB? 
  cokda: 
  

  

  Fig. 
  i 
  a. 
  View 
  of 
  right 
  side 
  of 
  spine, 
  portion 
  of 
  inferior 
  wall 
  broken 
  away 
  

  

  to 
  view 
  inner 
  surface' 
  .f 
  the 
  opposite 
  wall: 
  4 
  '<, 
  do.. 
  •■ 
  m 
  

  

  near 
  middle, 
  the 
  anterior 
  border 
  uppermost. 
  St. 
  Louis; 
  Alton. 
  Illiie 
  

   Mr. 
  Butters. 
  

  

  Dbepanacanthi's 
  bevebsus. 
  St. 
  J. 
  and 
  \Y 
  253 
  

  

  Fig. 
  5 
  n. 
  View 
  of 
  right 
  side 
  of 
  spine: 
  5 
  '«. 
  c, 
  do.. 
  Iran- 
  | 
  I 
  tip 
  and 
  

  

  near 
  dorsal 
  line. 
  St, 
  Louis; 
  Alton, 
  Illinois. 
  Mr. 
  Butt' 
  

  

  PbTCOVBCOI 
  rALCATUS. 
  St. 
  J. 
  and 
  \V 
  

  

  Fig. 
  C 
  a. 
  View 
  of 
  iplne 
  from 
  the 
  right 
  side, 
  h.-i«e;partially 
  : 
  u.«- 
  

  

  verso 
  section 
  toward 
  tip. 
  St. 
  Louis: 
  B 
  H 
  -hlngton 
  

  

  University. 
  

  

  