﻿412 
  ACTINOPTERYGTI. 
  

  

  41079. 
  Another 
  fine 
  specimen 
  of 
  the 
  anterior 
  border 
  of 
  the 
  pectoral 
  

   fin 
  ; 
  Chalk, 
  Merstham, 
  Surrey. 
  

  

  Presented 
  by 
  Prof. 
  N. 
  S. 
  Maskelyne, 
  1868. 
  

  

  35554. 
  Anterior 
  portion 
  of 
  similar 
  fin 
  ; 
  Gault, 
  Folkestone. 
  

  

  Purchased, 
  1859. 
  

  

  46961. 
  Fragment 
  of 
  still 
  larger 
  pectoral 
  ; 
  Lower 
  Chalk, 
  Burham, 
  

   Kent. 
  Purchased, 
  1876. 
  

  

  P. 
  1480. 
  Two 
  fragments 
  of 
  similar 
  fin 
  ; 
  Chalk, 
  Lewes. 
  

  

  Egerton 
  Coll. 
  

  

  4070. 
  Fragment 
  with 
  more 
  widely 
  spaced 
  anterior 
  eminences, 
  de- 
  

   scribed 
  and 
  figured 
  by 
  Agassiz 
  (op. 
  cit. 
  vol. 
  iii. 
  p. 
  58, 
  

   pi. 
  x. 
  a. 
  fig. 
  2) 
  under 
  the 
  name 
  of 
  Ptychodus 
  arcuatus, 
  and 
  

   also 
  figured 
  by 
  Mantell 
  (op. 
  cit. 
  pi. 
  xl. 
  fig. 
  3) 
  ; 
  Upper 
  

   Chalk, 
  Lewes. 
  Mantell 
  Coll. 
  

  

  P. 
  7254-55. 
  Small 
  fragments 
  apparently 
  of 
  similar 
  fins 
  ; 
  Cambridge 
  

   Greensand. 
  Jesson 
  Coll. 
  

  

  4075. 
  Anterior 
  portion 
  of 
  more 
  delicate 
  pectoral 
  fin, 
  with 
  less 
  pro- 
  

   minently 
  sinuous 
  margin, 
  described 
  and 
  figured 
  by 
  Agassiz 
  

   (op. 
  cit. 
  p. 
  58, 
  pi. 
  x. 
  a. 
  fig. 
  4) 
  under 
  the 
  name 
  of 
  Ptychodus 
  

   gibberulus; 
  Chalk, 
  Lewes. 
  Mantell 
  Coll. 
  

  

  49747-48. 
  Two 
  fragments 
  of 
  similar 
  fins 
  ; 
  Lower 
  Chalk, 
  Southeram, 
  

   Lewes. 
  C 
  apron 
  Coll. 
  

  

  41695. 
  Fine 
  fin 
  showing 
  a 
  basal 
  bone; 
  Chalk, 
  Kent. 
  

  

  Toidmin 
  Smith 
  Coll. 
  

  

  39066. 
  Similar 
  but 
  more 
  imperfect 
  fin 
  ; 
  Chalk, 
  Harisham, 
  Kent. 
  

  

  Boiverbank 
  Coll. 
  

  

  33176. 
  Two 
  fragments 
  of 
  similar 
  fin 
  ; 
  Chalk, 
  Burham. 
  

  

  Purchased, 
  1857. 
  

  

  36092-93, 
  47280. 
  Three 
  imperfect 
  specimens 
  of 
  similar 
  fin 
  ; 
  Lower 
  

   Chalk, 
  Dorking, 
  Surrey. 
  

  

  Purchased, 
  1861, 
  and 
  Gardner 
  Coll. 
  

  

  49733. 
  Fine 
  fin 
  and 
  another 
  small 
  specimen 
  ; 
  Dorking. 
  

  

  Capron 
  Coll. 
  

  

  49029-30. 
  Two 
  similar 
  specimens 
  ; 
  English 
  Chalk. 
  

  

  Mrs. 
  Smith's 
  Coll. 
  

  

  