﻿358 
  ACTINOPTEftYGII. 
  

  

  and 
  the 
  hinder 
  margin 
  is 
  not 
  serrated. 
  That 
  the 
  scales 
  do 
  not 
  

   pertain 
  to 
  Lepidotus 
  is 
  shown 
  not 
  only 
  by 
  their 
  form, 
  but 
  also 
  by 
  

   the 
  non-production 
  of 
  the 
  angles 
  of 
  the 
  overlapped 
  anterior 
  border. 
  

   Form. 
  Sf 
  Loc. 
  Turonian 
  : 
  Kent 
  and 
  Surrey. 
  

  

  P. 
  4705. 
  Group 
  of 
  associated 
  scales, 
  to 
  be 
  regarded 
  as 
  the 
  type 
  

   specimen 
  ; 
  Lower 
  Chalk, 
  Burham, 
  Kent. 
  

  

  EnnisJcillen 
  Coll. 
  

  

  P. 
  1106. 
  Two 
  smaller 
  groups 
  of 
  imperfect 
  scales, 
  one 
  labelled 
  by 
  

   Agassiz 
  ; 
  Burham. 
  Egerton 
  Coll. 
  

  

  P. 
  6526. 
  Group 
  of 
  six 
  associated 
  scales, 
  tbrce 
  figured 
  in 
  Proc. 
  Geol. 
  

   Assoc, 
  vol. 
  x. 
  pi. 
  i. 
  fig. 
  2 
  ; 
  Blue 
  Bell 
  Hill, 
  Burham. 
  

  

  Presented 
  by 
  S. 
  J. 
  Hawkins, 
  Esq., 
  1891. 
  

  

  P. 
  7567. 
  Abraded 
  scale 
  ; 
  Lower 
  Chalk. 
  Dorking, 
  Surrey. 
  

  

  Purchased. 
  

  

  An 
  imperfect 
  fish 
  much 
  resembling 
  Neorliombolepis, 
  but 
  differing 
  

   in 
  its 
  more 
  powerful 
  dentition 
  and 
  the 
  subdivision 
  of 
  the 
  gular 
  

   plate 
  into 
  four 
  pieces, 
  is 
  described 
  as 
  follows 
  : 
  — 
  

  

  Otomitla 
  sjoeciosa, 
  J. 
  Felix, 
  Palaeontogr. 
  vol. 
  xxxvii. 
  (1891), 
  p. 
  189, 
  

   pi. 
  xxix. 
  fig. 
  3, 
  pi. 
  xxx. 
  figs. 
  3-5. 
  — 
  Neocomian 
  ; 
  Cerro 
  

   de 
  la 
  Yirgen, 
  Tlaxiaco, 
  Oaxaca, 
  Mexico. 
  [Head 
  with 
  

   scattered 
  scales 
  and 
  vertebrae 
  ; 
  J. 
  Felix 
  Collection, 
  

   Leipzig.] 
  

  

  Genus 
  LOPHIOSTOMUS, 
  Egerton. 
  

  

  [Figs. 
  & 
  Descript. 
  Brit. 
  Organic 
  Remains, 
  dec. 
  vi. 
  (Mem. 
  

  

  Geol. 
  Surv. 
  1852), 
  no. 
  10.] 
  

  

  An 
  imperfectly 
  known 
  genus 
  with 
  relatively 
  large 
  head, 
  which 
  

   appears 
  to 
  have 
  been 
  much 
  depressed. 
  External 
  head-bones 
  and 
  

   the 
  opercular 
  bones 
  robust, 
  more 
  or 
  less 
  ornamented 
  with 
  tubercles 
  

   and 
  rugae 
  of 
  enamel 
  ; 
  the 
  roof 
  of 
  the 
  cranium 
  raised 
  into 
  a 
  promi- 
  

   nent 
  boss 
  on 
  each 
  side 
  immediately 
  behind 
  the 
  orbit; 
  jaws 
  

   relatively 
  very 
  large, 
  the 
  maxilla 
  with 
  a 
  straight 
  or 
  slightly 
  

   concave 
  dentigerous 
  border, 
  and 
  the 
  premaxillae 
  fused 
  with 
  the 
  

   ethmoid 
  ; 
  teeth 
  in 
  regular 
  series, 
  large 
  and 
  hollow 
  on 
  the 
  margin 
  

   of 
  the 
  jaw, 
  minute 
  on 
  the 
  inner 
  bones, 
  and 
  those 
  of 
  the 
  dentary 
  

   larger 
  than 
  those 
  of 
  the 
  maxilla 
  ; 
  suboperculum 
  nearly 
  half 
  as 
  

   large 
  as 
  the 
  operculum, 
  which 
  is 
  quadrangular 
  but 
  truncated 
  at 
  the 
  

   postero-superior 
  angle 
  ; 
  gular 
  plate 
  very 
  large. 
  [Axial 
  skeleton 
  of 
  

   trunk 
  not 
  certainly 
  known.] 
  Fin-rays 
  robust, 
  externally 
  ornamented 
  ; 
  

   paired 
  fins 
  without 
  fulcra, 
  the 
  pelvic 
  pair 
  relatively 
  small 
  ; 
  [median 
  

  

  