﻿Vol. 
  53.] 
  OF 
  THE 
  CHALK 
  EOCK. 
  389 
  

  

  the 
  name 
  of 
  P. 
  Barroisi. 
  The 
  only 
  English 
  specimens 
  that 
  I 
  have 
  

   seen 
  were 
  collected 
  by 
  Mr. 
  R. 
  M. 
  Brydone. 
  P. 
  nodosa 
  itself 
  comes 
  

   from 
  Touraine. 
  

  

  Affinities. 
  — 
  P. 
  nodosa, 
  Dujardin, 
  differs 
  from 
  P. 
  Barroisi 
  in 
  being 
  

   about 
  four 
  times 
  larger, 
  more 
  elongated, 
  and 
  ornamented 
  with 
  large, 
  

   simple, 
  widely-separated 
  ribs. 
  

  

  Distribution. 
  — 
  England 
  : 
  Chalk 
  Rock 
  of 
  Winchester. 
  France 
  : 
  

   zones 
  of 
  Belemnitella 
  plena, 
  Inoceramas 
  labiatus, 
  Terebratuliaa 
  

   gracilis, 
  Epiaster 
  brevis, 
  & 
  Belemnitella 
  quadrata, 
  north 
  and 
  east 
  

   of 
  the 
  Paris 
  basin. 
  Saxony 
  : 
  Planer-Kalk 
  of 
  Strehlen. 
  Bohemia 
  : 
  

   Reuss's 
  specimens 
  came 
  from 
  the 
  Planer-Kalk 
  and 
  Pyrope-Sand 
  of 
  

   Triziblitz, 
  and 
  the 
  Planer-Mergel 
  of 
  Weberschan. 
  Pritsch's 
  examples 
  

   are 
  from 
  the 
  Teplitz 
  Beds. 
  

  

  Pamily 
  Cardiidse, 
  Lamarck. 
  

   Genus 
  Caedium, 
  Linnaeus, 
  1758. 
  

  

  Caedium 
  tueoniense, 
  sp. 
  nov. 
  (PI. 
  XXVII. 
  figs. 
  20-22.) 
  

  

  Description. 
  — 
  Shell 
  small, 
  oblique, 
  oval, 
  inflated, 
  higher 
  than 
  

   long 
  ; 
  umbones 
  prominent. 
  Ornamented 
  with 
  plain 
  ribs, 
  separated 
  

   by 
  furrows 
  of 
  about 
  the 
  same 
  width 
  ; 
  with 
  indistinct 
  pits 
  in 
  the 
  

   furrows. 
  About 
  ten 
  ribs 
  in 
  a 
  space 
  of 
  3 
  mm. 
  Size 
  of 
  a 
  specimen 
  : 
  

   length=6 
  mm. 
  ; 
  height 
  = 
  7 
  mm. 
  

  

  Affinities. 
  — 
  The 
  ornamentation 
  is 
  coarser 
  and 
  the 
  shell 
  more 
  

   oblique 
  than 
  in 
  C. 
  lineolatum, 
  Reuss. 
  The 
  ornamentation 
  is 
  some- 
  

   what 
  similar 
  to 
  that 
  in 
  C. 
  cenomanense, 
  d'Orbigny, 
  but 
  the 
  ribs 
  are 
  

   less 
  numerous 
  than 
  in 
  that 
  species, 
  and 
  the 
  form 
  of 
  the 
  shell 
  is 
  

   quite 
  different. 
  

  

  Remarks. 
  — 
  This 
  is 
  a 
  rare 
  species 
  ; 
  the 
  only 
  forms 
  seen 
  are 
  in 
  the 
  

   Montagu 
  Smith 
  Collection. 
  

  

  Distribution. 
  — 
  Chalk 
  Rock 
  of 
  Cuckhamsley. 
  

  

  Caedium 
  sp., 
  cf. 
  cenomanense, 
  d'Orb. 
  (PI. 
  XXVII. 
  figs. 
  23 
  & 
  24.) 
  

   1843-47. 
  A. 
  d'Orbigny, 
  ' 
  Pal. 
  Fran*?. 
  Terr. 
  Cret.' 
  vol. 
  iii. 
  p. 
  37 
  & 
  pi. 
  ccxlix. 
  f. 
  5-9. 
  

  

  Remarks. 
  — 
  A 
  species 
  of 
  Cardium, 
  agreeing 
  in 
  form 
  with 
  C. 
  ceno- 
  

   manense, 
  is 
  represented 
  by 
  several 
  specimens 
  from 
  Cuckhamsley, 
  but 
  

   all 
  are 
  in 
  the 
  condition 
  of 
  internal 
  casts, 
  so 
  that 
  their 
  determination 
  

   must 
  remain 
  doubtful 
  for 
  the 
  present. 
  Size 
  of 
  a 
  specimen 
  : 
  length 
  

   = 
  9 
  mm.; 
  height 
  = 
  9 
  mm.; 
  thickness 
  = 
  8 
  mm. 
  

  

  Distribution. 
  — 
  Chalk 
  Rock 
  of 
  Cuckhamsley 
  (Montagu 
  Smith 
  

   Collection.) 
  

  

  Caedium 
  sp., 
  cf. 
  Mailleancm, 
  d'Orbigny. 
  

  

  1843-47. 
  A. 
  d'Orbigny, 
  'Pal. 
  Franc. 
  Terr. 
  Cret,' 
  vol. 
  iii. 
  p. 
  40 
  & 
  pi. 
  cclvi.f. 
  7-12. 
  

  

  Remarks. 
  — 
  There 
  is 
  one 
  specimen 
  in 
  the 
  Montagu 
  Smith 
  Collec- 
  

   tion 
  which 
  probably 
  belongs 
  to 
  this 
  species, 
  but 
  only 
  a 
  small 
  portion 
  

   of 
  the 
  shell 
  on 
  the 
  posterior 
  part 
  of 
  the 
  right 
  valve 
  is 
  preserved. 
  

  

  Distribution.— 
  Chalk 
  Rock 
  of 
  Cuckhamsley. 
  D'Orbigny 
  obtained 
  

   specimens 
  from 
  the 
  Lower 
  Chalk 
  of 
  Rouen, 
  etc. 
  

  

  