﻿S2 
  ACTINOPTERYGII. 
  

  

  The 
  course 
  of 
  the 
  sensory 
  canals 
  on 
  the 
  trunk 
  can 
  be 
  traced 
  by 
  

   perforations 
  and 
  notches 
  in 
  the 
  scales, 
  which 
  never 
  produce 
  a 
  super- 
  

   ficial 
  ridge. 
  There 
  is 
  one 
  principal 
  lateral 
  line, 
  as 
  usual, 
  and 
  a 
  

   second 
  proceeds 
  above 
  on 
  each 
  side 
  from 
  the 
  outer 
  supratemporal 
  to 
  

   the 
  origin 
  of 
  the 
  dorsal 
  fin, 
  but 
  apparently 
  not 
  beyond. 
  

  

  The 
  species 
  of 
  Lejpidotus 
  are 
  numerous, 
  and 
  many 
  are 
  only 
  

   imperfectly 
  known. 
  The 
  following 
  synopsis 
  of 
  those 
  described 
  

   below 
  shows 
  the 
  nature 
  of 
  some 
  of 
  the 
  specific 
  characters 
  : 
  — 
  

  

  I. 
  Inner 
  teeth 
  on 
  long 
  pedicles, 
  not 
  much 
  en- 
  

  

  larged. 
  Scales 
  smooth. 
  

  

  Parietals 
  less 
  than 
  half 
  as 
  long 
  as 
  frontals, 
  

   which 
  are 
  three 
  times 
  as 
  long 
  as 
  broad 
  

   and 
  united 
  by 
  slightly 
  wavy 
  suture 
  ; 
  

   operculum 
  two-thirds 
  as 
  broad 
  as 
  deep 
  ; 
  

   scales 
  in 
  part 
  serrated 
  elvensis, 
  p. 
  84. 
  

  

  Ditto, 
  but 
  median 
  frontal 
  suture 
  more 
  wavy, 
  

  

  parietals 
  longer, 
  and 
  fish 
  more 
  elongated 
  semiserratus, 
  p. 
  85. 
  

  

  Parietals 
  at 
  least 
  half 
  as 
  long 
  as 
  frontals, 
  

   which 
  meet 
  in 
  a 
  nearly 
  straight 
  median 
  

   suture 
  ; 
  operculum 
  two-thirds 
  as 
  broad 
  

   as 
  deep 
  ; 
  scales 
  not 
  serrated 
  gallineki, 
  p. 
  87. 
  

  

  Parietals 
  half 
  as 
  long 
  as 
  frontals, 
  which 
  are 
  

   twice 
  as 
  long 
  as 
  broad 
  and 
  united 
  by 
  

   deeply 
  sinuous 
  suture; 
  operculum 
  two- 
  

   thirds 
  as 
  broad 
  as 
  deep 
  ; 
  principal 
  flank- 
  

   scales 
  conspicuously 
  denticulated 
  latifrons, 
  p. 
  89. 
  

  

  Parietals 
  less 
  than 
  half 
  as 
  long 
  as 
  frontals, 
  

   which 
  are 
  three 
  times 
  as 
  long 
  as 
  broad 
  

   and 
  united 
  by 
  nearly 
  straight 
  median 
  

   suture 
  ; 
  principal 
  flank-scales 
  conspicu- 
  

   ously 
  denticulated 
  macrocheirus, 
  p. 
  90. 
  

  

  Operculum 
  twice 
  as 
  deep 
  as 
  its 
  maximum 
  

   breadth, 
  which 
  is 
  contained 
  more 
  than 
  

   three 
  times 
  in 
  the 
  length 
  of 
  the 
  head 
  ; 
  

   very 
  few 
  scales 
  serrated, 
  but 
  those 
  of 
  

   lateral 
  line 
  notched 
  notopterus, 
  p. 
  92. 
  

  

  Parietals 
  about 
  one-third 
  as 
  long 
  as 
  frontals, 
  

   which 
  are 
  three 
  times 
  as 
  long 
  as 
  broad 
  

   and 
  united 
  by 
  nearly 
  straight 
  median 
  

   suture 
  ; 
  operculum 
  somewhat 
  less 
  than 
  

   twice 
  as 
  deep 
  as 
  its 
  maximum 
  breadth, 
  

   which 
  is 
  contained 
  nearly 
  three 
  times 
  in 
  

   the 
  length 
  of 
  the 
  head 
  ; 
  few 
  scales 
  in 
  part 
  

   serrated, 
  but 
  those 
  of 
  lateral 
  line 
  notched, 
  minor, 
  p. 
  94. 
  

  

  II. 
  Inner 
  teeth 
  on 
  comparatively 
  short 
  pedicles, 
  

  

  much 
  enlarged. 
  

   (a.) 
  Scales 
  smooth. 
  

   Operculum 
  nearly 
  twice 
  as 
  deep 
  as 
  broad 
  ; 
  

  

  