﻿170 
  ACTINOPTEETGn. 
  

  

  non-denticulated 
  • 
  but 
  in 
  the 
  type 
  and 
  only 
  known 
  specimen 
  none 
  

   of 
  the 
  scales 
  of 
  the 
  flank 
  are 
  exposed 
  from 
  the 
  outer 
  aspect, 
  their 
  

   hinder 
  border 
  being 
  thus 
  obscured. 
  

  

  Form. 
  6f 
  Loc. 
  Purbeck 
  Beds 
  : 
  (?) 
  Dorsetshire. 
  

  

  P. 
  7433. 
  Type 
  specimen 
  ; 
  probably 
  from 
  the 
  neighbourhood 
  of 
  

   Swanage. 
  Old 
  Collection. 
  

  

  Ophiopsis 
  breviceps, 
  Egerton. 
  

  

  1852. 
  Ophiopsis 
  breviceps, 
  Sir 
  P. 
  Egerton, 
  Figs. 
  & 
  Descript. 
  Brit. 
  

   Organic 
  Remains 
  (Mem. 
  Geol. 
  Surv.), 
  dec. 
  vi. 
  no. 
  6, 
  pi. 
  vi. 
  

  

  Type. 
  Nearly 
  complete 
  fish 
  ; 
  Museum 
  of 
  Practical 
  Geology. 
  

  

  A 
  robust 
  species 
  of 
  small 
  size, 
  attaining 
  a 
  length 
  of 
  about 
  0*12. 
  

   Head 
  with 
  opercular 
  apparatus 
  occupying 
  slightly 
  less 
  than 
  one- 
  

   quarter 
  of 
  the 
  total 
  length 
  ; 
  maximum 
  depth 
  of 
  trunk 
  twice 
  as 
  

   great 
  as 
  the 
  width 
  of 
  the 
  caudal 
  pedicle 
  and 
  contained 
  nearly 
  four- 
  

   and-a-half 
  times 
  in 
  the 
  total 
  length. 
  Head 
  and 
  opercular 
  bones 
  

   coarsely 
  ornamented 
  with 
  tubercles 
  and 
  rugae 
  ; 
  teeth 
  elongate- 
  

   conical. 
  Dorsal 
  fin 
  comprising 
  not 
  less 
  than 
  35 
  rays 
  and 
  occupying 
  

   the 
  greater 
  part 
  of 
  the 
  hinder 
  two-thirds 
  of 
  the 
  trunk, 
  not 
  so 
  deep 
  

   as 
  the 
  trunk 
  at 
  its 
  point 
  of 
  origin 
  ; 
  pelvic 
  fins 
  arising 
  almost 
  at 
  the 
  

   middle 
  point 
  between 
  the 
  pectorals 
  and 
  the 
  caudal. 
  Scales 
  smooth 
  

   and 
  somewhat 
  concave 
  externally, 
  with 
  a 
  coarsely 
  serrated 
  hinder 
  

   border. 
  

  

  Form. 
  Sf 
  Loc. 
  Purbeck 
  Beds 
  : 
  Wiltshire. 
  

  

  P. 
  3608. 
  A 
  typical 
  specimen 
  with 
  scattered 
  squamation 
  and 
  head- 
  

   bones, 
  and 
  the 
  fins 
  only 
  shown 
  in 
  impression 
  ; 
  Wockley. 
  

   near 
  Tisbury. 
  The 
  premaxillae 
  exhibit 
  an 
  upwardly- 
  

   ascending 
  extension, 
  and 
  the 
  outer 
  aspect 
  of 
  an 
  operculum 
  

   shows 
  the 
  coarsely 
  rugose 
  character 
  of 
  the 
  surface-orna- 
  

   ment. 
  The 
  vertebrae, 
  as 
  usual, 
  are 
  very 
  delicate. 
  

  

  EnnisJcillen 
  Coll. 
  

  

  46410. 
  Imperfect 
  hinder 
  two-thirds 
  of 
  the 
  trunk, 
  with 
  remains 
  of 
  

   dorsal 
  fin 
  ; 
  near 
  Tisbury. 
  Cunnington 
  Coll. 
  

  

  P. 
  583. 
  Fragmentary 
  specimen 
  labelled 
  by 
  Egerton 
  as 
  the 
  counter- 
  

   part 
  of 
  the 
  original 
  of 
  his 
  fig. 
  2, 
  loc. 
  cit. 
  ; 
  "Wockley, 
  near 
  

   Tisbury. 
  Egerton 
  Coll. 
  

  

  P. 
  1094. 
  Two 
  specimens 
  exhibiting 
  vertebrae, 
  scales, 
  and 
  other 
  

   fragments; 
  Wockley. 
  Egerton 
  Coll. 
  

  

  