﻿528 
  ACTItfOPTERYGII. 
  

  

  P. 
  922, 
  P. 
  3686. 
  Imperfect 
  anterior 
  portion 
  of 
  fish, 
  in 
  counterpart 
  ; 
  

   Kimmeridge. 
  Egerton 
  <$f 
  Enniskillen 
  Colls. 
  

  

  P. 
  6031. 
  Middle 
  portion 
  of 
  trunk, 
  showing 
  part 
  of 
  the 
  dorsal 
  and 
  

   anal 
  fins 
  ; 
  Dorsetshire. 
  

  

  Presented 
  by 
  George 
  Clifton, 
  Esq., 
  1889. 
  

  

  P. 
  922 
  a, 
  P. 
  3686 
  a. 
  Fragments 
  ; 
  Kimmeridge. 
  

  

  Egerton 
  6f 
  Enniskillen 
  Colls. 
  

  

  The 
  following 
  specimens 
  of 
  Thrissops 
  are 
  not 
  specifically 
  deter- 
  

   mined: 
  — 
  

  

  37086. 
  Well-preserved 
  specimen 
  0-36 
  in 
  length, 
  in 
  counterpart, 
  

   exhibiting 
  all 
  the 
  fins: 
  Lower 
  Kimmeridgian 
  (Litho- 
  

   graphic 
  Stone), 
  Solenhofen. 
  The 
  head 
  with 
  opercular 
  

   apparatus 
  is 
  contained 
  nearly 
  seven 
  times 
  in 
  the 
  total 
  

   length 
  of 
  the 
  fish 
  ; 
  the 
  maximum 
  depth 
  of 
  the 
  trunk 
  equals 
  

   the 
  length 
  of 
  the 
  head 
  with 
  opercular 
  apparatus, 
  and 
  is 
  

   contained 
  nearly 
  five 
  times 
  in 
  the 
  length 
  of 
  the 
  trunk 
  from 
  

   the 
  pectoral 
  arch 
  to 
  the 
  base 
  of 
  the 
  caudal 
  fin. 
  Vertebrae 
  

   and 
  fins 
  almost 
  as 
  in 
  the 
  type 
  species, 
  but 
  the 
  anal 
  rela- 
  

   tively 
  more 
  elongated 
  by 
  the 
  spacing 
  of 
  the 
  rays, 
  and 
  the 
  

   caudal 
  much 
  less 
  deeply 
  forked, 
  with 
  broader 
  lobes. 
  

  

  Haberlein 
  Coll. 
  

  

  P. 
  937, 
  P. 
  3676. 
  Remains 
  of 
  slender 
  fish 
  originally 
  about 
  0-2 
  in 
  

   length, 
  the 
  anterior 
  portion 
  in 
  counterpart 
  ; 
  Oxford 
  Clay, 
  

   Christian 
  Malford, 
  near 
  Chippenham, 
  Wiltshire. 
  The 
  

   specimen 
  is 
  labelled 
  Leptolej>is 
  costalis 
  by 
  Egerton, 
  and 
  is 
  

   evidently 
  intended 
  to 
  be 
  the 
  type 
  specimen 
  of 
  that 
  species 
  

   named 
  in 
  Quart. 
  Journ. 
  Geol. 
  Soc. 
  vol. 
  i. 
  (1845), 
  p. 
  231. 
  

   The 
  length 
  of 
  the 
  head 
  with 
  opercular 
  apparatus 
  must 
  have 
  

   considerably 
  exceeded 
  the 
  maximum 
  depth 
  of 
  the 
  trunk, 
  

   but 
  it 
  is 
  very 
  imperfect 
  ; 
  the 
  caudal 
  region 
  is 
  also 
  almost 
  

   wanting. 
  All 
  the 
  vertebral 
  centra 
  are 
  somewhat 
  longer 
  

   than 
  deep, 
  and 
  28 
  pairs 
  of 
  stout 
  ribs 
  are 
  exhibited. 
  The 
  

   long 
  and 
  delicate 
  intermuscular 
  bones 
  are 
  conspicuous 
  as 
  

   usual 
  above 
  the 
  vertebral 
  column. 
  Of 
  the 
  fins, 
  only 
  a 
  

   fragment 
  of 
  the 
  pectoral 
  pair 
  remains. 
  

  

  Egerton 
  Sf 
  Enniskillen 
  Colls. 
  

  

  P. 
  417 
  a. 
  Imperfect 
  remains 
  of 
  a 
  fish 
  about 
  0*35 
  in 
  length; 
  Pur- 
  

   beck 
  Beds, 
  Swanage. 
  The 
  cranium 
  is 
  wanting 
  from 
  the 
  

   head, 
  while 
  portions 
  of 
  the 
  vertebral 
  column 
  are 
  missing 
  

   from 
  the 
  middle 
  of 
  the 
  abdominal, 
  and 
  the 
  front 
  of 
  the 
  

  

  