﻿EUGNATHID^E. 
  347 
  

  

  greater 
  than 
  the 
  depth 
  of 
  the 
  bone 
  at 
  their 
  insertion 
  ; 
  all 
  the 
  teeth, 
  

   both 
  upper 
  and 
  lower, 
  very 
  slender 
  at 
  the 
  apex 
  and 
  often 
  incurved. 
  

   Symphysial 
  end 
  of 
  the 
  only 
  known 
  dentary 
  bone 
  considerably 
  

   curved 
  downwards. 
  

  

  Form. 
  6f 
  Loc. 
  Portlandian 
  : 
  Isle 
  of 
  Portland. 
  Kirnmeridgian 
  : 
  

   Dorsetshire. 
  

  

  P. 
  6035. 
  Type 
  specimen, 
  shown 
  of 
  one-half 
  the 
  natural 
  size 
  in 
  

   PL 
  VII. 
  fig. 
  4 
  ; 
  Portland 
  Stone, 
  Isle 
  of 
  Portland. 
  Both 
  

   bone 
  and 
  teeth 
  are 
  much 
  fractured, 
  but 
  the 
  general 
  form 
  

   of 
  the 
  maxilla 
  is 
  distinct 
  except 
  at 
  its 
  hinder 
  extremity. 
  

   The 
  very 
  slender 
  small 
  teeth 
  are 
  indicated 
  posteriorly, 
  

   and 
  the 
  attenuated 
  incurved 
  apex 
  is 
  also 
  shown 
  on 
  the 
  

   principal 
  teeth, 
  some 
  of 
  which 
  are 
  fractured 
  to 
  expose 
  the 
  

   inner 
  cavity. 
  Presented 
  by 
  George 
  Clifton, 
  Esq., 
  1890. 
  

  

  P. 
  6034 
  a. 
  Middle 
  portion 
  of 
  a 
  similar 
  maxilla, 
  with 
  teeth 
  showing 
  

  

  the 
  smooth 
  solid 
  apex 
  ; 
  Portland 
  Stone. 
  Isle 
  of 
  Portland. 
  

  

  Presented 
  by 
  George 
  Clifton, 
  Esq., 
  1890. 
  

  

  42381. 
  Anterior 
  portion 
  of 
  left 
  maxilla 
  and 
  other 
  fragments 
  ; 
  

   Portland 
  Stone, 
  Isle 
  of 
  Portland. 
  Purchased, 
  1870. 
  

  

  40719. 
  Right 
  maxilla, 
  inner 
  aspect, 
  wanting 
  the 
  hinder 
  portion 
  

   but 
  with 
  well-preserved 
  remains 
  of 
  teeth 
  showing 
  their 
  

   characteristic 
  form 
  : 
  Kimmeridge 
  Clay, 
  Dorsetshire. 
  

  

  Purchased, 
  1867. 
  

  

  P. 
  6034. 
  Imperfect 
  right 
  dentary, 
  shown 
  from 
  the 
  outer 
  aspect 
  of 
  

   one-half 
  the 
  natural 
  size 
  in 
  PI. 
  VII. 
  fig. 
  5, 
  remarkable 
  

   for 
  the 
  crowding 
  of 
  the 
  anterior 
  teeth 
  and 
  the 
  downward 
  

   curvature 
  of 
  the 
  bone 
  towards 
  the 
  symphysis 
  (s.) 
  ; 
  Port- 
  

   land 
  Stone, 
  Isle 
  of 
  Portland. 
  

  

  Presented 
  by 
  George 
  Clifton, 
  Esq., 
  1890. 
  

  

  Caturus 
  (Ditaxiodus) 
  impar 
  (Owen). 
  

   1866. 
  Ditaxiodus 
  impar, 
  R. 
  Owen, 
  Geol. 
  Mag. 
  vol. 
  iii. 
  p. 
  107, 
  pis. 
  iv. 
  & 
  v. 
  

  

  Type. 
  Jaws 
  ; 
  British 
  Museum. 
  

  

  The 
  type 
  species 
  of 
  the 
  so-called 
  genus 
  Ditaxiodus, 
  known 
  only 
  

   by 
  the 
  jaws, 
  which 
  indicate 
  a 
  fish 
  perhaps 
  about 
  1 
  metre 
  in 
  length. 
  

   Maxilla 
  thick 
  but 
  less 
  deepened 
  than 
  in 
  any 
  of 
  the 
  preceding 
  

   species, 
  much 
  arched 
  throughout 
  the 
  greater 
  part 
  of 
  its 
  length, 
  and 
  

   the 
  height 
  of 
  the 
  middle 
  teeth 
  considerably 
  exceeding 
  the 
  depth 
  of 
  

   the 
  bone 
  at 
  their 
  insertion. 
  All 
  the 
  teeth, 
  both 
  upper 
  and 
  lower, 
  

  

  