﻿334 
  On 
  the 
  Classification 
  of 
  the 
  Order 
  Synentognathi. 
  

  

  Family 
  1. 
  Hemirhamphidse. 
  

  

  Prsemaxillaries 
  anteriorly 
  forming 
  a 
  flat 
  triangular 
  ex- 
  

   pansion 
  ; 
  maxillaries 
  firmly 
  united 
  to 
  prsemaxillaries 
  ; 
  teeth 
  

   in 
  jaws 
  small, 
  compressed, 
  usually 
  tricuspid; 
  third 
  Tipper 
  

   pharyngeals 
  ankylosed. 
  Vertebrae 
  49 
  to 
  55 
  ; 
  parapophyses 
  

   strong, 
  nearly 
  horizontal. 
  Pectoral 
  fins 
  short 
  or 
  moderately 
  

   long. 
  

  

  Genera 
  : 
  Cobitopsis 
  (probably 
  including 
  Chriodorus) 
  , 
  

   Arrhamphus, 
  Hemirhamphus, 
  Hemirhamphodon, 
  Zenarcho- 
  

   pterus, 
  Dermntogenys, 
  Oxy 
  porhamphus 
  , 
  Euleptorhamphus. 
  

  

  Hemirhamphus 
  occurs 
  in 
  the 
  Upper 
  Eocene 
  oil 
  Monte 
  

   Bolca. 
  

  

  Cobitopsis 
  acutus, 
  from 
  the 
  Lower 
  Miocene 
  of 
  France, 
  is 
  

   very 
  closely 
  related 
  to 
  Chriodorus 
  atherinoides 
  from 
  the 
  coast 
  

   of 
  Florida. 
  Dr. 
  Smith 
  Woodward 
  has 
  permitted 
  me 
  to 
  

   examine 
  examples 
  of 
  the 
  extinct 
  species, 
  which 
  I 
  have 
  com- 
  

   pared 
  with 
  specimens 
  of 
  C. 
  atherinoides. 
  The 
  two 
  agree 
  in 
  

   almost 
  every 
  detail 
  ; 
  the 
  form, 
  position, 
  and 
  structure 
  of 
  the 
  

   fins 
  and 
  the 
  number 
  of 
  rays 
  are 
  exactly 
  the 
  same 
  ; 
  the 
  jaws, 
  

   opercles, 
  pectoral 
  arch, 
  &c. 
  are 
  extremely 
  similar 
  in 
  the 
  two 
  

   species, 
  and 
  the 
  number 
  of 
  vertebrae 
  is 
  nearly 
  or 
  quite 
  

   identical,, 
  In 
  an 
  example 
  of 
  Chriodorus 
  atherinoides 
  I 
  count 
  

   16 
  dorsal, 
  17 
  anal, 
  12 
  pectoral, 
  6 
  pelvic, 
  and 
  13 
  branched 
  

   caudal 
  rays, 
  and 
  I 
  find 
  these 
  numbers 
  also 
  in 
  Cobitopsis 
  

   acutus 
  ; 
  I 
  find 
  49 
  vertebrae 
  in 
  C. 
  atherinoides, 
  and 
  approxi- 
  

   mately 
  this 
  number 
  in 
  C. 
  acutus. 
  

  

  In 
  making 
  a 
  restoration 
  of 
  the 
  extinct 
  species 
  Dr. 
  Smith 
  

   Wood 
  ward 
  * 
  has 
  evidently 
  been 
  influenced 
  by 
  Mr. 
  Boulenger's 
  

   opinion 
  that 
  this 
  fish 
  was 
  related 
  to 
  Ammodytes. 
  The 
  broad 
  

   cleithrum 
  of 
  the 
  Hemirhamphidse 
  is 
  represented 
  as 
  the 
  

   enlarged 
  suboperculum 
  of 
  the 
  Ammodytidse, 
  and 
  the 
  pectorals 
  

   are 
  shown 
  as 
  symmetrical 
  and 
  placed 
  low, 
  whereas 
  they 
  

   appear 
  to 
  me 
  to 
  be 
  asymmetrical 
  and 
  placed 
  high. 
  C. 
  acutus 
  

   has 
  usually 
  been 
  described 
  as 
  toothless, 
  but 
  I 
  believe 
  that 
  I 
  

   can 
  recognize 
  traces 
  of 
  small 
  teeth 
  in 
  the 
  jaws 
  of 
  one 
  of 
  the 
  

   specimens. 
  

  

  In 
  C. 
  acutus 
  the 
  head 
  is 
  longer 
  than 
  in 
  C. 
  atherinoides, 
  

   measuring 
  more 
  than 
  \ 
  of 
  the 
  length 
  of 
  the 
  fish 
  to 
  the 
  base 
  

   of 
  the 
  caudal, 
  the 
  lower 
  jaw 
  seems 
  to 
  be 
  longer, 
  more 
  than 
  ^ 
  

   the 
  length 
  of 
  the 
  head, 
  and 
  the 
  snout 
  is 
  apparently 
  more 
  

   produced. 
  

  

  * 
  Cat. 
  Fossil 
  Fish. 
  iv. 
  p. 
  355 
  (1901). 
  

  

  