﻿330 
  

  

  Mr. 
  C. 
  T. 
  Eegan 
  on 
  the 
  

  

  This 
  classification 
  was 
  adopted 
  by 
  Jordan 
  and 
  Evermann 
  

   (Bull. 
  U.S. 
  Nat. 
  Mus. 
  xlvii. 
  1896, 
  p. 
  707) 
  except 
  that 
  the 
  

   subfamilies 
  were 
  given 
  family 
  rank. 
  The 
  diagnostic 
  cha- 
  

   racters 
  were 
  practically 
  unchanged, 
  except 
  that 
  the 
  position 
  

   and 
  size 
  of 
  the 
  additional 
  bone 
  in 
  the 
  lower 
  jaw 
  were 
  correctly 
  

   indicated. 
  Ridewood 
  (P. 
  Z. 
  S. 
  1904, 
  ii. 
  p. 
  72) 
  has 
  pointed 
  out 
  

   that 
  the 
  names 
  " 
  addentary 
  " 
  and 
  " 
  intradentary 
  " 
  proposed 
  

   by 
  Gill 
  were 
  based 
  on 
  a 
  misconception 
  ; 
  the 
  best 
  name 
  for 
  this 
  

   bone 
  is 
  that 
  given 
  by 
  Ridewood, 
  namely 
  " 
  sesamoid 
  articu- 
  

   lare." 
  The 
  development 
  of 
  this 
  bone 
  is 
  more 
  or 
  less 
  propor- 
  

   tional 
  to 
  the 
  length 
  of 
  the 
  jaw 
  and 
  the 
  strength 
  of 
  the 
  

   dentition 
  ; 
  it 
  is 
  largest 
  in 
  Tylosurus 
  and 
  smallest 
  in 
  E.vocoetus 
  

   (c/. 
  text-fig.) 
  . 
  None 
  of 
  the 
  characters 
  used 
  by 
  Gill 
  to 
  charac- 
  

   terize 
  his 
  two 
  families 
  is 
  really 
  distinctive. 
  In 
  Scombresox 
  

  

  Inner 
  view 
  of 
  left 
  ramus 
  of 
  lower 
  jaw 
  of 
  : 
  1. 
  JExocoetus 
  arcticepa, 
  

   2. 
  C'hriodorus 
  atherinoides. 
  3. 
  Scombresox 
  saurus. 
  4. 
  Belone 
  belone. 
  

  

  s, 
  sesamoid 
  articulare 
  ; 
  ar, 
  articulare 
  ; 
  an, 
  angulare 
  ; 
  d, 
  dentary. 
  

  

  the 
  form 
  of 
  the 
  maxillary 
  and 
  its 
  mode 
  of 
  attachment 
  to 
  

   the 
  prsemaxillary 
  are 
  exactly 
  as 
  in 
  the 
  Belonidse, 
  and 
  the 
  

   pharyngeal 
  bones 
  and 
  teeth 
  are 
  much 
  more 
  similar 
  to 
  those 
  

   of 
  Belone 
  and 
  Tylosurus 
  than 
  to 
  those 
  of 
  Hemirhamphus 
  or 
  

   Exoccetus 
  (cf. 
  PI. 
  IX.). 
  Zygapophyses 
  are 
  equally 
  well 
  

   developed 
  in 
  all 
  the 
  Synentognaths 
  ; 
  throughout 
  the 
  group 
  

   the 
  neural 
  arch 
  of 
  each 
  vertebra 
  has 
  on 
  each 
  side 
  a 
  posterior 
  

  

  