﻿PLATE 
  XXX. 
  

  

  Stkophostylus 
  cyclostomus 
  Hall. 
  

   Page 
  176. 
  

  

  Fig. 
  1. 
  The 
  back 
  of 
  a 
  small 
  specimen, 
  showing 
  the 
  rotundity 
  of 
  the 
  volutions 
  

  

  and 
  an 
  unusually 
  high 
  spire. 
  

   Fig. 
  2. 
  An 
  oblique 
  front 
  view 
  of 
  a 
  larger 
  characteristic 
  specimen, 
  showing 
  the 
  

  

  obliquity 
  of 
  the 
  aperture. 
  

   Figs. 
  3, 
  4. 
  Summit 
  and 
  lateral 
  views 
  of 
  a 
  specimen 
  of 
  usual 
  form 
  and 
  size. 
  

   Fig. 
  5. 
  The 
  aperture 
  of 
  a 
  more 
  elevated 
  specimen, 
  showing 
  the 
  character 
  of 
  the 
  

  

  inner 
  lip 
  and 
  columella. 
  

   Fig. 
  6. 
  Dorsal 
  view 
  of 
  a 
  specimen 
  with 
  very 
  rotund 
  volutions. 
  

   Fig 
  7. 
  The 
  aperture 
  of 
  a 
  more 
  erect 
  and 
  elevated 
  form, 
  showing 
  some 
  slight 
  

  

  differences 
  from 
  fig. 
  5. 
  

   Figs. 
  8-10. 
  Dorsal, 
  basal, 
  and 
  oblique 
  front 
  views 
  of 
  a 
  large, 
  perfect 
  specimen, 
  

  

  showing 
  the 
  direction 
  of 
  the 
  striae, 
  the 
  aperture, 
  etc. 
  

   Figs. 
  11, 
  12. 
  Front 
  and 
  oblique 
  lateral 
  views 
  of 
  a 
  specimen 
  showing 
  the 
  form 
  

  

  of 
  the 
  aperture, 
  inner 
  lip, 
  and 
  twisting 
  of 
  the 
  columella. 
  

   Fig. 
  13. 
  An 
  enlargement 
  of 
  the 
  surface-striae 
  of 
  a 
  full-grown 
  specimen, 
  showing 
  

  

  the 
  transverse 
  striae 
  of 
  growth, 
  and 
  the 
  finer 
  revolving 
  lines. 
  

  

  Strophostylus 
  cyclostomus 
  var. 
  disjunctus 
  n. 
  var. 
  

  

  Page 
  177. 
  

   Figs. 
  14, 
  15. 
  The 
  opposite 
  sides 
  of 
  a 
  specimen 
  referred 
  with 
  doubt 
  to 
  this 
  spe- 
  

   cies. 
  The 
  outer 
  volution 
  has 
  become 
  free, 
  so 
  that 
  its 
  generic 
  char- 
  

   acters 
  are 
  obliterated; 
  but 
  the 
  surface-striae 
  and 
  the 
  upper 
  volu- 
  

   tions 
  are 
  precisely 
  the 
  same 
  as 
  8. 
  cyclostomus. 
  

  

  Cyrtolites 
  sinuosus 
  Hall. 
  

  

  Page 
  178. 
  

  

  Figs. 
  16-18. 
  Lateral, 
  front 
  and 
  dorsal 
  views 
  of 
  a 
  specimen 
  enlarged 
  to 
  three 
  

   diameters. 
  

  

  Bellerophon" 
  tuber 
  Hall. 
  

  

  Page 
  177. 
  

  

  Figs. 
  19, 
  20. 
  Dorsal 
  and 
  lateral 
  views 
  of 
  a 
  specimen, 
  enlarged 
  to 
  two 
  diameters. 
  

  

  