﻿Classificati 
  m 
  of 
  the 
  Order 
  Iaiomi. 
  127 
  

  

  more 
  slender 
  and 
  less 
  distinctly 
  flattened 
  ; 
  pectoral 
  of 
  two 
  well- 
  

   separated 
  portions, 
  the 
  upper 
  of 
  a 
  very 
  long 
  bifid 
  ray, 
  usually 
  

   with 
  1 
  or 
  2 
  short 
  rays 
  in 
  its 
  axil, 
  the 
  lower 
  of 
  from 
  8 
  to 
  14 
  

   simple 
  filamentous 
  rays 
  ; 
  lowest 
  caudal 
  ray 
  not 
  excessively 
  

  

  prolonged 
  ; 
  eyes 
  present, 
  small 
  6. 
  Bathypterois. 
  

  

  III. 
  Body 
  more 
  or 
  less 
  compressed 
  ; 
  snout 
  more 
  or 
  less 
  produced 
  ; 
  

   maxillary 
  not 
  reaching 
  the 
  eye. 
  

  

  A. 
  Body 
  moderately 
  elongate, 
  somewhat 
  compressed; 
  dorsal 
  and 
  

  

  pelvic 
  fins 
  placed 
  well 
  forward 
  7. 
  Parasudis. 
  

  

  B. 
  Body 
  elongate, 
  strongly 
  compressed 
  ; 
  dorsal 
  and 
  pelvic 
  fins 
  placed 
  

  

  posteriorly. 
  

  

  No 
  strong 
  canines 
  8. 
  Paralepis 
  * 
  

  

  Several 
  long 
  canine 
  teeth 
  on 
  each 
  side 
  of 
  the 
  lower 
  

  

  jaw 
  9> 
  Sudis. 
  

  

  The 
  new 
  genus 
  Bathysauropsis 
  is 
  here 
  established 
  for 
  

   Chlorophthalmus 
  gracilis, 
  Giinth. 
  It 
  differs 
  from 
  Ghloro- 
  

   phthalmus 
  in 
  the 
  more 
  slender 
  body, 
  depressed 
  head, 
  somewhat 
  

   smaller 
  eyes, 
  broader 
  interorbital 
  region, 
  broader 
  and 
  more 
  

   depressed 
  snout, 
  larger 
  mouth, 
  pelvic 
  fins 
  further 
  apart 
  and 
  

   more 
  advanced, 
  pectorals 
  placed 
  higher, 
  &c. 
  In 
  fact, 
  it 
  is 
  in 
  

   every 
  way 
  intermediate 
  between 
  Chlorophthalmus 
  on 
  the 
  one 
  

   hand 
  and 
  Ipnops 
  and 
  Benthosaurus 
  on 
  the 
  other. 
  Ipnops 
  

   resembles 
  it 
  in 
  form, 
  scaling, 
  structure, 
  and 
  position 
  of 
  the 
  

   fins, 
  mouth, 
  dentition, 
  &c, 
  and 
  it 
  is 
  open 
  to 
  question 
  whether 
  

   anything 
  is 
  gained 
  by 
  placing 
  it 
  in 
  a 
  different 
  family 
  on 
  

   account 
  of 
  the 
  characters 
  of 
  specialization 
  indicated 
  in 
  the 
  

   synopsis. 
  Benthosaurus 
  and 
  liemipterois 
  (a 
  new 
  genus 
  with 
  

   Bathypterois 
  guentheri, 
  Alcock, 
  as 
  the 
  type) 
  lead 
  from 
  

   Bathysauropsis 
  to 
  Bithypterois 
  f. 
  

  

  * 
  M. 
  Dollo 
  (Proc. 
  R. 
  Soc. 
  Edinh. 
  xxviii. 
  1908, 
  p. 
  59) 
  recognizes 
  a 
  

   family 
  Paralepidoe 
  to 
  include 
  Paralepis, 
  Sudis, 
  and 
  five 
  other 
  genera. 
  Of 
  

   these, 
  Nutolepis, 
  Dollo, 
  seems 
  to 
  differ 
  from 
  Paralepis 
  only 
  in 
  having 
  a 
  

   longer 
  adipose 
  fin, 
  and 
  Lestidium, 
  Gilb., 
  is 
  doubtfully 
  distinct 
  from 
  Sudis. 
  

   Neosudis, 
  Casteln., 
  and 
  Playyodus 
  (Alepidosaurus) 
  are 
  not, 
  in 
  my 
  opinion, 
  

   members 
  of 
  this 
  group, 
  and 
  Prymnothonus 
  houkeri 
  is 
  a 
  larval 
  form 
  of 
  

   uncertain 
  relationships. 
  

  

  f 
  The 
  species 
  of 
  Bathypterois 
  may 
  be 
  provisionally 
  arranged 
  thus 
  : 
  — 
  

  

  I. 
  Lowest 
  pectoral 
  ray 
  very 
  long 
  quadrifilis, 
  Giinth. 
  

  

  II. 
  Lowest 
  pectoral 
  ray 
  not 
  greatly 
  prolonged. 
  

  

  A. 
  Lower 
  part 
  of 
  pectoral 
  8 
  or 
  9 
  rayed. 
  

  

  Outermost 
  pelvic 
  rays 
  slightly 
  produced 
  j 
  ^S«, 
  jK^r. 
  

  

  Outermost 
  pelvic 
  rays 
  moderately 
  produced 
  .... 
  \ 
  fafin^yjtf\ 
  ' 
  

   Outermost 
  pelvic 
  rays 
  considerably 
  produced. 
  . 
  . 
  . 
  lonyicauda, 
  Giinth. 
  

  

  B. 
  Lower 
  part 
  of 
  pectoral 
  10 
  or 
  11 
  rayed. 
  

  

  Outermost 
  pelvic 
  ray 
  scarcely 
  produced 
  antennatus, 
  Gilb. 
  

  

  Outermost 
  pelvic 
  ray 
  moderately 
  produced 
  \pectorahs, 
  Garm. 
  

  

  1 
  - 
  ' 
  ( 
  atncolor, 
  Alcock. 
  

  

  