﻿PACHYCOEMID^. 
  411 
  

  

  P. 
  7257. 
  Four 
  expanded 
  haemal 
  bones 
  doubtfully 
  ascribed 
  to 
  this 
  

   genus 
  ; 
  Cambridge 
  Greensand. 
  Jesson 
  Coll. 
  

  

  P. 
  7258. 
  Ten 
  expanded 
  haemal 
  bones 
  doubtfully 
  ascribed 
  to 
  this 
  

   genus, 
  deeper 
  than 
  the 
  preceding 
  specimens 
  and 
  some 
  

   exhibiting 
  feeble 
  vertical 
  flutings 
  ; 
  Cambridge 
  Greensand. 
  

  

  Coll. 
  

  

  30259, 
  35160, 
  35394. 
  Eight 
  expanded 
  haemals 
  ; 
  Cambridge 
  Green- 
  

   sand. 
  Purchased, 
  1855, 
  1859. 
  

  

  P. 
  7256. 
  Other 
  still 
  more 
  deeply 
  expanded 
  haemals 
  of 
  the 
  form 
  

   provisionally 
  ascribed 
  to 
  this 
  genus 
  by 
  W. 
  Davies, 
  Geol. 
  

   Mag. 
  [2] 
  vol. 
  v. 
  p. 
  256 
  ; 
  Cambridge 
  Greensand. 
  

  

  Jesson 
  Coll. 
  

  

  35160 
  a, 
  35351. 
  Two 
  similarly 
  expanded 
  haemals, 
  imperfect 
  but 
  dis- 
  

   playing 
  slight 
  vertical 
  furrows 
  ; 
  Cambridge 
  Greensand. 
  

  

  Purchased, 
  1859. 
  

  

  47191, 
  P. 
  38. 
  Two 
  small 
  expanded 
  haemals 
  of 
  similar 
  form 
  ; 
  Gault, 
  

   Folkestone. 
  Gardner 
  Coll. 
  

  

  49102. 
  Imperfect 
  large 
  example 
  of 
  similarly 
  expanded 
  haemal 
  0-125 
  

   in 
  depth 
  ; 
  Chalk, 
  Kent. 
  Mrs. 
  Smith's 
  Coll. 
  

  

  38027. 
  Smaller 
  specimen 
  ; 
  Chalk, 
  Lewes. 
  Purchased, 
  1863. 
  

  

  P. 
  5120. 
  Still 
  smaller 
  specimen 
  ; 
  Neocomian, 
  Choroskowo, 
  Russia. 
  

  

  Purchased, 
  1886. 
  

  

  P. 
  1483. 
  Small 
  expanded 
  haemal 
  overlapped 
  by 
  caudal 
  fin-rays 
  ; 
  

   Chalk, 
  Sussex. 
  Egerton 
  Coll. 
  

  

  4074, 
  4099. 
  Two 
  fragments 
  of 
  pectoral 
  fins 
  showing 
  wavy 
  anterior 
  

   border, 
  described 
  and 
  figured 
  by 
  Agassiz 
  (Poiss. 
  Foss. 
  

   vol. 
  iii. 
  1837, 
  p. 
  57, 
  pi. 
  x. 
  a. 
  figs. 
  1, 
  3) 
  under 
  the 
  name 
  of 
  

   Ptychodus 
  spectabilis 
  ; 
  Upper 
  Chalk, 
  Lewes. 
  The 
  first 
  

   specimen 
  is 
  also 
  figured 
  by 
  Mantell 
  (Geol. 
  Sussex, 
  1822, 
  

   pi. 
  xxxix.) 
  as 
  " 
  a 
  dorsal 
  fin, 
  or 
  radius, 
  of 
  a 
  fish 
  allied 
  to 
  

   the 
  genus 
  Balistes." 
  Mantell 
  Coll. 
  

  

  39471. 
  Larger 
  portion 
  of 
  a 
  similar 
  fin 
  ; 
  English 
  Chalk. 
  

  

  Bowerbank 
  Coll. 
  

  

  35374. 
  Small 
  fragment 
  of 
  similar 
  fin 
  ; 
  Chalk, 
  Cambridge. 
  

  

  Purchased, 
  1859. 
  

  

  