﻿340 
  ACTINOPTERTGII. 
  

  

  It 
  is 
  not 
  improbable 
  that 
  the 
  undefined 
  name 
  Caturus 
  buclclandi 
  

   (L. 
  Agassiz, 
  Poiss. 
  Foss. 
  vol. 
  ii. 
  pt. 
  ii. 
  1844, 
  p. 
  119) 
  pertains 
  to 
  this 
  

   species. 
  It 
  was 
  originally 
  applied 
  to 
  a 
  specimen 
  from 
  Lyme 
  Regis 
  

   exhibiting 
  the 
  head 
  and 
  anterior 
  portion 
  of 
  trunk, 
  but 
  the 
  present 
  

   writer 
  has 
  not 
  been 
  able 
  to 
  discover 
  this 
  fossil. 
  

  

  Form. 
  Sf 
  Loc. 
  Lower 
  Lias 
  : 
  Dorsetshire. 
  

  

  All 
  the 
  following 
  specimens 
  were 
  obtained 
  from 
  the 
  neighbourhood 
  

   of 
  Lyme 
  Regis 
  : 
  — 
  

  

  38121. 
  Head 
  with 
  abdominal 
  region 
  exposed 
  from 
  the 
  left 
  side, 
  

   shown 
  of 
  one-half 
  the 
  natural 
  size 
  in 
  PI. 
  IX. 
  fig. 
  1. 
  The 
  

   cranium 
  is 
  too 
  much 
  crushed 
  for 
  examination, 
  and 
  the 
  

   facial 
  bones 
  are 
  mostly 
  imperfect 
  and 
  fractured. 
  The 
  

   short 
  and 
  deep 
  premaxillae 
  (prmc.) 
  bear 
  a 
  few 
  large 
  slender 
  

   teeth; 
  the 
  maxilla 
  (mcc.) 
  exhibits 
  a 
  close 
  series 
  of 
  small 
  

   slender 
  teeth, 
  and 
  there 
  is 
  a 
  supram 
  axillary 
  bone 
  (s.mx.). 
  

   The 
  mandible 
  exhibits 
  very 
  large, 
  widely-spaced 
  teeth 
  in 
  

   the 
  dentary 
  bone 
  (d.), 
  and 
  there 
  are 
  indications 
  of 
  the 
  

   ascending 
  plate 
  of 
  bone 
  behind 
  the 
  tooth-bearing 
  margin. 
  

   The 
  form 
  and 
  proportions 
  of 
  the 
  opercular 
  bones 
  (op., 
  

   s.op., 
  i. 
  op., 
  p. 
  op.) 
  are 
  shown, 
  while 
  the 
  large 
  size 
  of 
  the 
  

   upper 
  branch 
  iostegal 
  ray 
  (or.l) 
  and 
  of 
  the 
  gular 
  plate 
  (g.) 
  

   is 
  noteworthy. 
  The 
  left 
  post-temporal 
  (p.t.), 
  clavicle, 
  

   and 
  supraclavicle 
  are 
  partly 
  exhibited, 
  and 
  there 
  are 
  

   remains 
  of 
  the 
  postclavicular 
  plates. 
  The 
  pectoral 
  fin 
  is 
  

   nearly 
  complete 
  ; 
  its 
  anterior 
  rays 
  are 
  remarkably 
  straight, 
  

   and 
  it 
  appears 
  to 
  have 
  been 
  fringed 
  with 
  slender 
  fulcra; 
  

   only 
  four 
  rays 
  of 
  the 
  left 
  pelvic 
  fin 
  remain, 
  but 
  the 
  large 
  

   slender 
  fulcra 
  are 
  well 
  preserved. 
  Of 
  the 
  dorsal 
  fin, 
  only 
  

   some 
  of 
  the 
  supports 
  are 
  shown. 
  The 
  position 
  of 
  the 
  

   notochord 
  is 
  marked 
  by 
  a 
  confused 
  line 
  of 
  hypocentra 
  and 
  

   pleurocentra 
  ; 
  the 
  ribs 
  are 
  long 
  and 
  the 
  neural 
  arches 
  

   short, 
  but 
  both 
  remarkably 
  slender. 
  Above 
  the 
  neural 
  

   arches 
  is 
  a 
  series 
  of 
  very 
  robust, 
  slightly 
  bent, 
  long 
  bones, 
  

   inclined 
  backwards, 
  commencing 
  shortly 
  behind 
  the 
  head 
  

   and 
  extending 
  even 
  beneath 
  the 
  supports 
  of 
  the 
  dorsal 
  

   fin 
  ; 
  and 
  these 
  appear 
  to 
  be 
  the 
  separate 
  neural 
  spines. 
  

   All 
  the 
  scales 
  are 
  smooth, 
  and 
  their 
  rhombic 
  form 
  is 
  well 
  

   shown 
  in 
  the 
  dorsal 
  region. 
  Purchased, 
  1864. 
  

  

  P. 
  897. 
  Head 
  and 
  fragment 
  of 
  abdominal 
  region 
  shown 
  from 
  the 
  

   right 
  side. 
  The 
  dentition 
  is 
  indicated 
  as 
  in 
  the 
  last 
  

   specimen. 
  Egerton 
  Coll. 
  

  

  P. 
  4377. 
  Remains 
  of 
  head 
  and 
  opercular 
  apparatus 
  in 
  indurated 
  

   Lias. 
  EnnisJcillen 
  Coll. 
  

  

  