﻿Aethub. 
  — 
  On, 
  the 
  Brown 
  Trout 
  introduced 
  into 
  Otarjo. 
  287 
  

  

  made 
  diagrams 
  of 
  tlie 
  heads 
  of 
  three 
  sea 
  trout 
  (being 
  the 
  only 
  ones 
  I 
  can 
  

   get), 
  two 
  of 
  which 
  are 
  at 
  present 
  in 
  my 
  possession, 
  and 
  one 
  belongs 
  to 
  our 
  

   Museum. 
  They 
  were 
  caught 
  in 
  Ofcago 
  harbour. 
  

  

  These 
  are 
  placed 
  beside 
  the 
  diagrams 
  of 
  S.fario 
  to 
  facilitate 
  comparison. 
  

   By 
  this 
  means 
  some 
  characteristic 
  distinctions 
  are 
  at 
  once 
  apparent. 
  In 
  

   each 
  head 
  the 
  lower 
  jaw 
  is 
  rather 
  longer 
  than 
  the 
  upper. 
  The 
  maxillary 
  

   does 
  not 
  project 
  beyond 
  a 
  vertical 
  line 
  drawn 
  from 
  the 
  posterior 
  margin 
  of 
  

   orbit. 
  The 
  lower 
  limb 
  is 
  narrower 
  and 
  the 
  upper 
  broader 
  relatively 
  than 
  

   in 
  the 
  two 
  heads 
  of 
  S. 
  fario, 
  and 
  the 
  whole 
  bone 
  is 
  finer 
  and 
  more 
  delicate. 
  

   Of 
  the 
  gill-covers, 
  the 
  greatest 
  difference 
  is 
  manifest 
  in 
  the 
  suboperculum, 
  

   which 
  roughly 
  approaches 
  a 
  sector 
  of 
  a 
  circle 
  in 
  outline, 
  its 
  lower 
  free 
  

   margin 
  being 
  nearly 
  semi-circular. 
  The 
  outline 
  of 
  integument 
  on 
  surface 
  

   of 
  this 
  bone 
  has 
  a 
  great 
  similarity 
  in 
  the 
  three 
  specimens, 
  and 
  differs 
  

   decidedly 
  from 
  that 
  on 
  the 
  same 
  bone 
  on 
  tbe 
  trout 
  heads. 
  The 
  spots 
  on 
  

   the 
  gill-covers 
  are 
  from 
  three 
  to 
  four, 
  while 
  in 
  the 
  trout 
  they 
  are 
  from 
  seven 
  

   to 
  eleven 
  ; 
  while 
  of 
  the 
  more 
  general 
  features 
  the 
  heads 
  are 
  short 
  and 
  

   deep, 
  and 
  fine 
  at 
  the 
  snout, 
  that 
  of 
  the 
  Museum 
  specimen 
  being 
  only 
  one- 
  

   fifth 
  of 
  the 
  whole 
  length 
  of 
  the 
  fish. 
  This 
  fish 
  measures- 
  — 
  length, 
  16 
  in. 
  ; 
  

   depth, 
  3f 
  in. 
  ; 
  head, 
  2J 
  in. 
  ; 
  and 
  scales 
  16 
  in 
  transverse 
  row 
  from 
  adipose 
  

   fin 
  backwards. 
  And 
  lastly, 
  these 
  three 
  fish 
  have 
  the 
  distinct 
  coating 
  of 
  

   bright 
  silvery 
  scales 
  all 
  over 
  their 
  bodies. 
  The 
  description 
  of 
  the 
  head 
  

   ( 
  S. 
  trutta), 
  given 
  by 
  Giinther 
  and 
  Yarrell, 
  agrees 
  very 
  well 
  with 
  the 
  above 
  

   three 
  specimens. 
  

  

  DESCEIPTION 
  OF 
  PLATE 
  XIII. 
  

  

  [Note. 
  — 
  Eeduced 
  one-half 
  from 
  the 
  author's 
  original 
  drawings.] 
  

  

  Salmo 
  fario. 
  

  

  Fig. 
  1. 
  Fac-simile 
  head 
  of 
  female 
  trout, 
  taken 
  in 
  Lee 
  Stream, 
  Oct., 
  1877 
  ; 
  weight, 
  4J 
  lbs. 
  

  

  2, 
  Fac-simile 
  of 
  dried 
  head 
  of 
  female 
  trout 
  taken 
  in 
  Upper 
  Taieri, 
  Mar. 
  1878 
  ; 
  weight 
  

  

  6 
  lbs. 
  6 
  ozs. 
  

   [Note. 
  — 
  The 
  numbers 
  represent 
  the 
  following 
  bones 
  : 
  1, 
  pre-maxillary 
  or 
  inter- 
  

   maxillary; 
  2, 
  maxillary 
  ; 
  3, 
  mandible; 
  4, 
  operculum; 
  5, 
  suboperculum; 
  

   6, 
  interoperculum 
  ; 
  7, 
  preoperculum. 
  

  

  Salmo 
  trutta. 
  

  

  3. 
  Fac-simile 
  head 
  of 
  female, 
  7 
  lbs. 
  weight, 
  got 
  in 
  harbom-, 
  Nov. 
  6, 
  1877. 
  

  

  i. 
  Do. 
  do. 
  dried 
  specimen, 
  1 
  lb. 
  weight, 
  got 
  in 
  Otago 
  Harbour, 
  Matck^ 
  

  

  1878. 
  

   §. 
  Hand-sketch 
  head 
  of 
  specimen, 
  IJlbs. 
  weight, 
  in 
  Otago 
  Museum 
  ; 
  caught 
  at 
  

   Otago 
  Heads, 
  Aprilj 
  1874. 
  

  

  