﻿ASPJDORHYNCHID^. 
  433 
  

  

  is 
  labelled 
  Belonostomus 
  ventralis, 
  apparently 
  in 
  Agassiz' 
  hand- 
  

   writing 
  ; 
  but 
  this 
  species 
  has 
  not 
  been 
  adequately 
  denned 
  

   (L. 
  Agassiz, 
  Bericht. 
  Yersamml. 
  deutsch. 
  ISTaturf., 
  Jena, 
  1836, 
  

   p. 
  127, 
  and 
  Poiss. 
  Foss. 
  vol. 
  ii. 
  pt. 
  ii. 
  1844, 
  pp. 
  143, 
  297), 
  and 
  

   the 
  type 
  specimen 
  is 
  said 
  by 
  A. 
  Wagner 
  to 
  be 
  specifically 
  inde- 
  

   terminable 
  (Abh. 
  k. 
  bay. 
  Akad. 
  Wiss., 
  math.-phys. 
  CI. 
  vol. 
  ix. 
  1863, 
  

   p. 
  692) 
  :— 
  

  

  P. 
  7577. 
  Remains 
  of 
  head 
  and 
  greater 
  portion 
  of 
  trunk 
  of 
  a 
  fish 
  in 
  

   counterpart, 
  noticed 
  and 
  figured 
  as 
  Serpens 
  marinus 
  in 
  

   J. 
  J. 
  Baier's 
  ' 
  Monumenta 
  rerum 
  petrificatarum 
  ' 
  (Nurem- 
  

   burg, 
  1757), 
  p. 
  10, 
  pi. 
  vi. 
  fig. 
  4 
  ; 
  Lithographic 
  Stone, 
  

   Solenhofen, 
  Bavaria. 
  Though 
  not 
  satisfactorily 
  shown, 
  

   it 
  seems 
  probable 
  that 
  the 
  much-attenuated 
  rostrum 
  

   projected 
  in 
  advance 
  of 
  the 
  mandible, 
  in 
  which 
  the 
  pre- 
  

   symphysial 
  bone 
  is 
  distinctly 
  separated 
  from 
  the 
  dentary 
  

   by 
  suture. 
  The 
  scales 
  are 
  comparatively 
  robust, 
  and 
  some 
  

   exhibit 
  a 
  tuberculated 
  or 
  rugose 
  ornament. 
  

  

  History 
  unknown. 
  

  

  Belonostomus 
  dorsetensis, 
  sp. 
  nov. 
  

   [Plate 
  XIV. 
  fig. 
  2.] 
  

  

  Type. 
  Imperfect 
  skull 
  and 
  mandible 
  ; 
  British 
  Museum. 
  

  

  A 
  species 
  of 
  moderate 
  size 
  known 
  only 
  by 
  the 
  head, 
  which 
  

   attains 
  a 
  length 
  of 
  about 
  0*115. 
  Postrum 
  much 
  attenuated 
  and 
  

   projecting 
  for 
  some 
  distance 
  in 
  advance 
  of 
  the 
  anterior 
  extremity 
  

   of 
  the 
  mandible 
  ; 
  the 
  blunt 
  anterior 
  extremity 
  of 
  the 
  dentary 
  bones 
  

   suturally 
  united 
  with 
  a 
  slight 
  excavation 
  in 
  the 
  presymphysial 
  bone, 
  

   and 
  the 
  median 
  series 
  of 
  widely-spaced 
  teeth 
  on 
  this 
  bone 
  relatively 
  

   large 
  • 
  ornament 
  of 
  cranium 
  consisting 
  of 
  fine 
  rugae 
  of 
  ganoine, 
  

   that 
  of 
  the 
  mandible 
  only 
  of 
  structural 
  rugae. 
  

  

  Form. 
  Sf 
  Log. 
  Kimmeridge 
  Clay 
  : 
  Dorsetshire. 
  

  

  P. 
  6175. 
  The 
  type 
  specimen 
  shown 
  of 
  the 
  natural 
  size 
  in 
  PI. 
  XIV. 
  

   fig. 
  2, 
  comprising 
  the 
  vertically 
  crushed 
  cranium 
  imper- 
  

   fect 
  behind, 
  the 
  left 
  ectopterygoid 
  (ecpt.) 
  and 
  imperfect 
  

   dentary 
  (d.), 
  and 
  the 
  presymphysial 
  bone 
  (ps.); 
  Kimme- 
  

   ridge 
  Clay, 
  Weymouth. 
  The 
  rostrum 
  is 
  shown 
  to 
  extend 
  

   considerably 
  in 
  advance 
  of 
  the 
  dentigerous 
  premaxillse 
  and 
  

   exhibits 
  a 
  longitudinal 
  groove 
  on 
  its 
  inferior 
  aspect 
  : 
  the 
  

   presymphysial 
  bone 
  is 
  dentigerous 
  throughout 
  its 
  length. 
  

   The 
  ectopterygoid 
  is 
  granulated 
  on 
  its 
  inner 
  face 
  and 
  

   bears 
  a 
  single 
  row 
  of 
  closely 
  arranged, 
  elongated 
  conical 
  

  

  PABT 
  III. 
  2 
  p 
  

  

  