﻿Powell. 
  — 
  On 
  Anatomy 
  of 
  Eegalecus 
  pacificus. 
  269 
  

  

  Art. 
  XXIII. 
  — 
  'Xotes 
  on 
  the 
  Anatomy 
  of 
  Eegalecus 
  pacificus, 
  von 
  Haast. 
  

   By 
  Llewellyn 
  Powell, 
  M.D., 
  F.L.S. 
  

   [Read 
  before 
  the 
  Philosophical 
  Institute 
  of 
  Ganterburij, 
  21st 
  February, 
  1878.] 
  

   Dr. 
  Haast, 
  in 
  the 
  descriptiou 
  of 
  Reyalecus 
  pacifiGus,'^ 
  speaks 
  of 
  tlie 
  silvery, 
  

   or 
  rather, 
  to 
  my 
  eye, 
  steely 
  coating 
  which 
  contributes 
  so 
  greatly 
  to 
  the 
  

   beauty 
  of 
  this 
  splendid 
  fish. 
  It 
  is 
  impossible 
  to 
  reproduce 
  it 
  either 
  in 
  a 
  

   drawing 
  or 
  to 
  perpetuate 
  it 
  by 
  any 
  mode 
  of 
  preservation, 
  as 
  it 
  is 
  detached 
  

   by 
  the 
  slightest 
  touch, 
  leaving 
  a 
  slimy, 
  silvery 
  patch 
  on 
  the 
  finger. 
  This 
  

   coating 
  has 
  been 
  described 
  as 
  consisting 
  of 
  minute 
  scales 
  by 
  one 
  observer, 
  

   and 
  by 
  another 
  as 
  scales 
  resembling 
  those 
  on 
  a 
  butterfly's 
  wing. 
  Such 
  is 
  

   not, 
  h')wever, 
  the 
  case. 
  It 
  is 
  evidently 
  a 
  secretion 
  similar 
  to 
  the 
  slimy 
  

   mucus 
  which 
  many 
  other 
  fishes 
  secrete 
  so 
  copiously. 
  The 
  microscope 
  

   resolves 
  the 
  steely 
  layer 
  into 
  myriads 
  of 
  exceedingly 
  minute 
  crystalline 
  

   needles, 
  or 
  elongated 
  tabular 
  prisms 
  with 
  oblique 
  ends. 
  The 
  largest 
  have 
  

   a 
  length 
  of 
  y^^ 
  inch 
  by 
  -sq-W 
  inch 
  in 
  breadth. 
  These 
  crystals 
  show 
  a 
  

   beautiful 
  metallic 
  lustre, 
  are 
  not 
  perishable, 
  do 
  not 
  polarize 
  light, 
  are 
  

   immediately 
  dissolved 
  in 
  liq. 
  potass., 
  but 
  are 
  insoluble 
  in 
  strong 
  acetic 
  

   acid. 
  I 
  cannot 
  ascertain 
  the 
  nature 
  of 
  the 
  silvery 
  coating 
  found 
  in 
  the 
  

   swim-bladder 
  of 
  certain 
  fishes, 
  such 
  as 
  Atherina, 
  which 
  was 
  formerly 
  used 
  

   in 
  the 
  manufacture 
  of 
  artificial 
  pearls. 
  It 
  is 
  not 
  improbably 
  of 
  a 
  similar 
  

   nature. 
  

  

  The 
  scales 
  of 
  the 
  lateral 
  line 
  are 
  peculiarly 
  formed, 
  being 
  very 
  long 
  in 
  

   proportion 
  to 
  their 
  breadth. 
  Their 
  length 
  slightly 
  exceeds 
  h; 
  inch, 
  while 
  

   their 
  breadth 
  does 
  not 
  exceed 
  -^-^ 
  inch 
  ; 
  one 
  extremity 
  is 
  slightly 
  expanded 
  

   or 
  spoon-shaped, 
  the 
  other 
  extremity 
  contracting 
  abruptly 
  to 
  a 
  point 
  which 
  

   articulates 
  firmly 
  with 
  the 
  dilated 
  extremity 
  of 
  the 
  following 
  scale. 
  These 
  

   scales 
  appear 
  to 
  me 
  to 
  be 
  tubular, 
  but 
  I 
  cannot 
  be 
  certain 
  of 
  this 
  as 
  they 
  

   shrivelled 
  in 
  drying. 
  

  

  I 
  noted 
  a 
  few 
  points 
  in 
  the 
  internal 
  anatomy. 
  I 
  regret 
  that 
  as 
  daylight 
  

   was 
  closing, 
  and 
  it 
  was 
  necessary 
  from 
  the 
  extremely 
  soft 
  and 
  watery 
  nature 
  

   of 
  the 
  integument 
  and 
  the 
  flesh 
  to 
  use 
  despatch 
  in 
  order 
  to 
  save 
  the 
  skin 
  in 
  

   good 
  condition, 
  I 
  was 
  unable 
  to 
  make 
  a 
  more 
  thorough 
  examination 
  of 
  this 
  

   interesting 
  fish. 
  

  

  The 
  gullet 
  terminated 
  at 
  2ft. 
  Tin. 
  from 
  the 
  snout 
  in 
  a 
  remarkably 
  

   elongated 
  muscular 
  stomach, 
  prolonged 
  backward 
  as 
  a 
  kind 
  of 
  caecum 
  to 
  a 
  

   length 
  of 
  4ft. 
  and 
  about 
  2in., 
  extending 
  2ft. 
  7in. 
  beyond 
  the 
  vent 
  in 
  a 
  

   diverticulum 
  from 
  the 
  peritoneal 
  cavity, 
  and 
  becoming 
  narrower 
  and 
  more 
  

   and 
  more 
  attenuated 
  until 
  it 
  becomes 
  so 
  exceedingly 
  thin 
  and 
  delicate 
  that, 
  

   with 
  the 
  utmost 
  care 
  in 
  dissection, 
  the 
  extremity 
  was 
  torn 
  and 
  imperfect. 
  

  

  The 
  pylorus 
  was 
  seated 
  immediately 
  by 
  the 
  side 
  of 
  the 
  cardiac 
  orifice, 
  

   being 
  provided 
  with 
  a 
  strong 
  muscular 
  ring, 
  the 
  duodesma, 
  if 
  one 
  may 
  so 
  

  

  * 
  Trans. 
  N.Z. 
  Inst. 
  X., 
  246-250, 
  pi. 
  vii. 
  

  

  