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  321 
  

  

  Ptycholepis 
  curta, 
  Egerton. 
  

  

  [Plate 
  X. 
  fig. 
  1.] 
  

  

  1854-55. 
  Ptycholepis 
  curtus, 
  Sir 
  P. 
  Egerton, 
  Ann. 
  Mag. 
  Nat. 
  Hist. 
  [2] 
  

   vol. 
  xiii. 
  p. 
  435, 
  and 
  Figs. 
  & 
  Descript. 
  Brit. 
  Organic 
  Remains, 
  

   dec. 
  viii. 
  (Mem. 
  Geol. 
  Surv.), 
  no. 
  8, 
  pi. 
  viii. 
  Suppl. 
  p. 
  1. 
  

  

  Type. 
  Crushed 
  fish 
  ; 
  British 
  Museum. 
  

  

  A 
  stout 
  species 
  of 
  moderate 
  size, 
  the 
  length 
  of 
  the 
  head 
  equalling 
  

   the 
  maximum 
  depth 
  of 
  the 
  trunk 
  and 
  contained 
  about 
  three-and-a- 
  

   half 
  times 
  in 
  the 
  total 
  length. 
  Pelvic 
  fins 
  opposed 
  to 
  the 
  hinder 
  

   portion 
  of 
  the 
  dorsal 
  ; 
  anal 
  fin 
  very 
  small 
  and 
  remote. 
  External 
  

   bones 
  and 
  fin-rays 
  ornamented 
  as 
  in 
  the 
  type 
  species 
  ; 
  the 
  scales 
  

   differing 
  in 
  the 
  presence 
  of 
  a 
  few 
  conspicuous 
  vertical 
  folds 
  of 
  

   ganoine 
  at 
  the 
  anterior 
  overlapped 
  border. 
  

  

  Form. 
  § 
  Loc. 
  Lower 
  Lias 
  : 
  Dorsetshire. 
  

  

  P. 
  6334. 
  The 
  type 
  specimen, 
  apparently 
  somewhat 
  shortened 
  by 
  

   crushing 
  ; 
  Lyme 
  Regis. 
  A 
  few 
  ossified 
  vertebral 
  rings, 
  

   with 
  their 
  robust 
  hsemal 
  arches, 
  are 
  seen 
  at 
  the 
  base 
  of 
  

   the 
  tail. 
  Beckles 
  Coll. 
  

  

  39493. 
  A 
  more 
  satisfactorily 
  preserved 
  fish, 
  shown 
  of 
  the 
  natural 
  

   size 
  in 
  PL 
  X. 
  fig. 
  1 
  ; 
  Lyme 
  Regis. 
  The 
  caudal 
  pedicle 
  is 
  

   accidentally 
  elongated 
  and 
  the 
  hinder 
  portion 
  of 
  the 
  

   dorsal 
  fin 
  is 
  wanting, 
  but 
  the 
  specimen 
  is 
  otherwise 
  

   nearly 
  complete. 
  The 
  maxilla 
  distinctly 
  shows 
  a 
  series 
  of 
  

   minute 
  conical 
  teeth, 
  while 
  the 
  characteristic 
  form 
  of 
  the 
  

   operculum 
  and 
  suboperculum 
  may 
  be 
  observed. 
  The 
  

   uppermost 
  branchiostegal 
  ray 
  is 
  conspicuously 
  ornamented. 
  

  

  Purchased, 
  1865. 
  

  

  P. 
  3692. 
  Imperfect 
  example 
  of 
  a 
  similar 
  fish, 
  evidently 
  the 
  second 
  

   specimen 
  described 
  by 
  Egerton, 
  loc. 
  cit. 
  Suppl. 
  p. 
  1 
  ; 
  Lyme 
  

   Regis. 
  Portions 
  of 
  the 
  smooth 
  branchiostegals 
  and 
  gular 
  

   plate 
  are 
  shown 
  : 
  and 
  there 
  is 
  evidence 
  of 
  biserial 
  fulcra 
  

   on 
  the 
  pectoral 
  fin. 
  EnnisJcillen 
  Coll. 
  

  

  P. 
  3692 
  a. 
  A 
  small, 
  much-abraded 
  specimen 
  ; 
  Lyme 
  Regis. 
  

  

  Enniskillen 
  Coll. 
  

  

  P. 
  859 
  a. 
  Imperfect 
  remains 
  of 
  head 
  and 
  squamation 
  ; 
  Lyme 
  

   Regis. 
  Many 
  of 
  the 
  scales 
  are 
  exposed 
  from 
  within, 
  and 
  

   demonstrate 
  the 
  absence 
  of 
  an 
  internal 
  rib. 
  

  

  Egerton 
  Coll. 
  

  

  PART 
  III. 
  Y 
  

  

  