﻿472 
  ACTINOI'TERIGII. 
  

  

  one-quarter 
  of 
  the 
  same 
  total 
  length. 
  All 
  the 
  head 
  and 
  opercular 
  

   bones 
  smooth 
  or 
  very 
  feebly 
  rugose 
  in 
  part 
  ; 
  angle 
  of 
  preoperculum 
  

   with 
  indications 
  of 
  radiating 
  ridges 
  ; 
  maxilla 
  not 
  much 
  arched 
  ; 
  

   teeth 
  comparatively 
  robust, 
  obtusely 
  pointed. 
  Fin-rays 
  smooth 
  and 
  

   stout 
  ; 
  fulcra 
  conspicuous. 
  Pelvic 
  fins 
  arising 
  far 
  in 
  advance 
  of 
  the 
  

   middle 
  point 
  of 
  the 
  trunk, 
  and 
  the 
  dorsal 
  fin 
  opposed 
  to 
  them. 
  

   Scales 
  large, 
  ornamented 
  with 
  coarse 
  oblique 
  ridges, 
  slightly 
  radiating, 
  

   and 
  terminating 
  at 
  the 
  hinder 
  margin 
  in 
  very 
  prominent 
  denticula- 
  

   tions 
  ; 
  several 
  series 
  of 
  flank-scales 
  deeper 
  than 
  broad 
  ; 
  the 
  orifices 
  

   of 
  the 
  lateral 
  line 
  prominent, 
  forming 
  a 
  ridge 
  on 
  the 
  caudal 
  

   pedicle 
  ; 
  the 
  ornament 
  on 
  the 
  caudal 
  region 
  becoming 
  feeble. 
  

   Form. 
  Sf 
  Loc. 
  Purbeckian 
  : 
  Dorsetshire. 
  

  

  P. 
  7583. 
  Imperfect 
  caudal 
  region, 
  the 
  type 
  specimen 
  described 
  and 
  

   figured 
  by 
  Agassiz, 
  loc. 
  cit. 
  ; 
  Swan 
  age. 
  Agassiz' 
  determi- 
  

   nation 
  of 
  the 
  dorsal 
  is 
  shown 
  by 
  Egerton 
  (loc. 
  cit.) 
  to 
  be 
  

   due 
  to 
  a 
  misinterpretation 
  of 
  some 
  broken 
  scales 
  and 
  

   inaccurate 
  drawing. 
  The 
  enlarged 
  scale 
  at 
  the 
  base 
  of 
  

   the 
  upper 
  caudal 
  lobe 
  is 
  pointed 
  at 
  each 
  extremity 
  and 
  

   very 
  feebly 
  rugose. 
  Mantell 
  Coll. 
  

  

  43038. 
  Greater 
  portion 
  offish, 
  much 
  crushed 
  and 
  distorted 
  ; 
  Swanage. 
  

  

  Purchased, 
  1871. 
  

  

  P. 
  6378. 
  Another 
  fine 
  specimen, 
  somewhat 
  distorted, 
  the 
  chief 
  basis 
  

   for 
  the 
  proportions 
  of 
  the 
  fish 
  given 
  in 
  the 
  above 
  diagnosis 
  ; 
  

   Swanage. 
  Beckles 
  Coll. 
  

  

  28445-46. 
  Two 
  more 
  imperfect 
  specimens, 
  displaying 
  parts 
  of 
  the 
  

   head-bones 
  and 
  squamation 
  ; 
  Swanage. 
  Cunnington 
  Coll. 
  

  

  P. 
  4411. 
  Eemains 
  of 
  head 
  with 
  well-preserved 
  abdominal 
  flank- 
  

   scales, 
  and 
  part 
  of 
  the 
  axial 
  skeleton 
  of 
  the 
  caudal 
  region 
  ; 
  

   Swanage. 
  The 
  neural 
  and 
  haemal 
  arches 
  in 
  the 
  caudal 
  

   region 
  are 
  short, 
  robust, 
  and 
  much 
  inclined 
  backwards, 
  

   and 
  the 
  vertebrae 
  are 
  delicate 
  broad 
  rings, 
  possibly 
  divided 
  

   into 
  hypocentral 
  and 
  pleurocentral 
  pieces. 
  

  

  Enniskillen 
  Coll. 
  

  

  P. 
  3605 
  a. 
  Heed 
  and 
  abdominal 
  region, 
  ventral 
  and 
  partly 
  lateral 
  

   aspect 
  ; 
  Swanage. 
  The 
  nearly 
  smooth 
  maxillae 
  and 
  den- 
  

   taries, 
  with 
  their 
  regular 
  series 
  of 
  obtusely 
  pointed 
  teeth, 
  

   are 
  well 
  shown 
  ; 
  and 
  fulcra 
  are 
  conspicuous 
  both 
  on 
  the 
  

   pectoral 
  and 
  pelvic 
  fins. 
  Enniskillen 
  Coll. 
  

  

  P, 
  1075. 
  Crushed 
  portion 
  of 
  caudal 
  region 
  ; 
  Upway, 
  near 
  Weymouth. 
  

  

  Egerton 
  Coll. 
  

  

  