﻿PLATE 
  XXIII. 
  

  

  Strophodonta 
  striata 
  Hall, 
  

  

  Page 
  152. 
  

  

  Fig. 
  1. 
  A 
  ventral 
  valve 
  showing 
  the 
  general 
  form 
  and 
  the 
  surface 
  characters. 
  

  

  Fig. 
  2. 
  The 
  dorsal 
  side 
  of 
  the 
  same. 
  

  

  Fig. 
  3. 
  A 
  profile 
  view, 
  showing 
  the 
  relative 
  convexity 
  and 
  the 
  bending 
  of 
  the 
  

   valves 
  at 
  the 
  cardinal 
  angles. 
  

  

  Fig. 
  4. 
  The 
  interior 
  of 
  a 
  dorsal 
  valve, 
  showing 
  the 
  cardinal 
  process, 
  and 
  crenu- 
  

   late 
  margins. 
  

  

  Fig. 
  5. 
  The 
  interior 
  of 
  a 
  ventral 
  valve, 
  showing 
  the 
  muscular 
  imprint, 
  the 
  car- 
  

   dinal 
  area 
  and 
  the 
  crenulations 
  on 
  the 
  hinge. 
  

  

  Fig'. 
  6. 
  An 
  enlargement 
  of 
  the 
  cardinal 
  process 
  of 
  the 
  dorsal 
  valve, 
  showing 
  the 
  

   grooving 
  of 
  the 
  posterior 
  face. 
  

  

  Strophonella 
  semifasciata 
  Hall. 
  

   Page 
  154. 
  

   Fig. 
  7. 
  The 
  ventral 
  side 
  of 
  a 
  large, 
  nearly 
  entire 
  specimen. 
  

  

  Fig. 
  8. 
  The 
  interior 
  of 
  an 
  imperfect 
  dorsal 
  valve, 
  referred 
  with 
  doubt 
  to 
  this 
  

   species, 
  showing 
  a 
  minute 
  cardinal 
  process 
  and 
  crenulated 
  hinge 
  

   line. 
  

  

  Strophodonta 
  profunda 
  Hall. 
  

   Page 
  151. 
  

  

  Fig. 
  9. 
  The 
  interior 
  of 
  a 
  ventral 
  valve, 
  showing 
  the 
  muscular 
  imprint 
  and 
  car- 
  

   dinal 
  area, 
  with 
  the 
  hinge 
  crenulations 
  extending 
  less 
  than 
  half 
  its 
  

   length. 
  

  

  Fig. 
  10. 
  The 
  exterior 
  of 
  an 
  imperfect 
  valve 
  partially 
  restored, 
  showing 
  the 
  

   character 
  of 
  the 
  striae. 
  

  

  Streptorhynchus 
  tenuis 
  Hall. 
  

  

  Page 
  150. 
  

  

  Fig. 
  11. 
  An 
  imperfect 
  ventral 
  valve, 
  showing 
  the 
  rounded 
  hinge 
  extremity 
  and 
  

  

  the 
  character 
  of 
  the 
  surface-striae. 
  

   Fig. 
  12. 
  A 
  dorsal 
  valve 
  showing 
  the 
  form 
  of 
  the 
  shell. 
  

  

  Fig. 
  13. 
  An 
  enlargement 
  of 
  the 
  surface, 
  showing 
  the 
  alternations 
  of 
  the 
  radiat- 
  

   ing 
  striae 
  and 
  the 
  finer 
  concentric 
  crenulating 
  lines. 
  

  

  