﻿EU0NATHIDJ3. 
  

  

  299 
  

  

  Eugnathus 
  altus, 
  sp. 
  nov. 
  

   [Plate 
  VI. 
  fig. 
  2.] 
  

   Type. 
  Imperfect 
  fish 
  ; 
  British 
  Museum. 
  

  

  A 
  species 
  of 
  moderate 
  size, 
  similar 
  iu 
  proportions 
  to 
  E. 
  serratus. 
  

   All 
  the 
  marginal 
  teeth 
  slender 
  and 
  in 
  close 
  series, 
  but 
  those 
  of 
  the 
  

   dentary 
  much 
  exceeding 
  those 
  of 
  the 
  maxilla 
  in 
  size. 
  Scales 
  

   relatively 
  smaller 
  than 
  in 
  any 
  of 
  the 
  foregoing 
  species. 
  

   Form. 
  Sf 
  Loc. 
  Lower 
  Lias 
  : 
  Dorsetshire. 
  

  

  P. 
  2029. 
  The 
  type 
  specimen 
  shown 
  of 
  two-thirds 
  the 
  natural 
  size 
  

   in 
  PI. 
  VI. 
  fig. 
  2 
  ; 
  Lyme 
  Regis. 
  The 
  bones 
  of 
  the 
  head 
  

   are 
  displaced 
  and 
  scattered, 
  but 
  some 
  are 
  well 
  shown. 
  

   The 
  dentary 
  (d.), 
  maxilla 
  (mx.), 
  and 
  premaxilla 
  (pmcc.) 
  

   exhibit 
  long, 
  slender 
  teeth 
  ; 
  while 
  portions 
  of 
  the 
  inner 
  

   bones 
  of 
  the 
  mouth 
  are 
  covered 
  with 
  granular 
  teeth. 
  The 
  

   form 
  of 
  the 
  hyomandibular 
  (Jim.) 
  is 
  also 
  well 
  shown, 
  

   and 
  the 
  suboperculum 
  (s.op.) 
  is 
  seen 
  to 
  bear 
  an 
  ascending 
  

   process 
  at 
  its 
  antero-superior 
  angle. 
  Behind 
  the 
  opercular 
  

   apparatus 
  the 
  clavicle 
  (cl.) 
  is 
  displayed, 
  showing 
  vertical 
  

   ribbing 
  on 
  the 
  outer 
  face 
  ; 
  but 
  only 
  fragments 
  of 
  the 
  

   pectoral, 
  pelvic, 
  dorsal, 
  and 
  caudal 
  fins 
  are 
  preserved, 
  

   while 
  the 
  anal 
  fin 
  is 
  wanting. 
  Some 
  of 
  the 
  anterior 
  flank- 
  

   scales 
  are 
  deeper 
  than 
  broad, 
  and 
  the 
  ornament 
  does 
  not 
  

   entirely 
  disappear 
  until 
  the 
  series 
  at 
  the 
  hinder 
  end 
  of 
  

   the 
  dorsal 
  fin. 
  Egerton 
  Coll. 
  

  

  Eugnathus 
  hastingsiae 
  (Agassiz). 
  

  

  [Plate 
  VII. 
  fig. 
  1.] 
  

  

  1843-44. 
  Pholidophorus 
  hastingsice, 
  L. 
  Agassiz, 
  Poiss. 
  Foss. 
  vol. 
  ii. 
  

   pt. 
  i. 
  p. 
  284, 
  pi. 
  xliia. 
  fig. 
  1. 
  

  

  Type. 
  Imperfect 
  fish 
  ; 
  British 
  Museum. 
  

  

  A 
  very 
  small 
  species, 
  attaining 
  a 
  length 
  of 
  about 
  0*1. 
  Length 
  of 
  

   head 
  with 
  opercular 
  apparatus 
  equalling 
  about 
  one-quarter, 
  and 
  

   maximum 
  depth 
  of 
  trunk 
  scarcely 
  more 
  than 
  one-sixth 
  of 
  the 
  total 
  

   length 
  of 
  the 
  fish; 
  maximum 
  width 
  of 
  caudal 
  pedicle 
  equalling 
  

   half 
  the 
  maximum 
  depth 
  of 
  the 
  trunk. 
  Head 
  elongated, 
  and 
  

   the 
  external 
  bones 
  almost 
  or 
  quite 
  smooth 
  ; 
  mandibular 
  teeth 
  few 
  

   and 
  stout, 
  maxillary 
  teeth 
  closely 
  arranged 
  and 
  slender 
  ; 
  operculum 
  

   very 
  slightly 
  broader 
  than 
  deep. 
  Fins 
  as 
  in 
  the 
  type 
  species. 
  

   Scales 
  very 
  feebly 
  ornamented 
  in 
  the 
  anterior 
  abdominal 
  region, 
  

   smooth 
  and 
  not 
  serrated 
  in 
  the 
  caudal 
  region. 
  

  

  Form. 
  <$f 
  Loc. 
  Lower 
  Lias 
  : 
  Leicestershire 
  and 
  Warwickshire. 
  

  

  