﻿FISHES. 
  

  

  is 
  not. 
  Second, 
  radula 
  attains 
  a 
  much 
  larger 
  size 
  than 
  

   circularis, 
  and 
  before 
  radula 
  is 
  mature 
  it 
  is 
  longer 
  and 
  broader 
  

   than 
  mature 
  circularis. 
  What 
  I 
  mean 
  by 
  mature 
  is, 
  that 
  in 
  

   radula 
  the 
  claspers 
  of 
  the 
  male 
  are 
  not 
  developed 
  beyond 
  two 
  

   inches 
  long 
  when 
  the 
  fish 
  itself 
  has 
  attained 
  a 
  size 
  consider- 
  

   ably 
  beyond 
  circularis, 
  in 
  which 
  these 
  organs 
  are 
  of 
  full 
  size, 
  

   and 
  the 
  fish 
  producing 
  young. 
  In 
  confirmation 
  of 
  this 
  I 
  

   have 
  taken 
  many 
  eggs 
  from 
  circularis, 
  and 
  have 
  had 
  them 
  

   hatched 
  out. 
  Third, 
  in 
  radula 
  the 
  male 
  is 
  always 
  much 
  

   smaller 
  than 
  the 
  female, 
  while 
  in 
  circularis 
  the 
  sexes 
  are 
  of 
  

   the 
  same 
  size. 
  Fourth, 
  the 
  claspers 
  in 
  radula 
  differ 
  in 
  form 
  

   from 
  those 
  of 
  circularis, 
  the 
  former 
  having 
  a 
  sharp 
  spine 
  on 
  

   the 
  edge 
  which 
  the 
  latter 
  never 
  has. 
  Fifth, 
  the 
  teeth 
  of 
  both 
  

   species, 
  though 
  similar 
  in 
  form, 
  are 
  not 
  identical. 
  Sixth, 
  the 
  

   form 
  of 
  the 
  two 
  fishes 
  is 
  very 
  different, 
  the 
  anterior 
  edges 
  

   of 
  radula 
  being 
  very 
  much 
  straight 
  er 
  than 
  those 
  of 
  circularis, 
  

   i.e., 
  the 
  anterior 
  edges 
  of 
  circularis 
  are 
  more 
  hollowed 
  out, 
  and 
  

   the 
  head 
  is 
  more 
  marked 
  off 
  from 
  the 
  body 
  than 
  in 
  radula. 
  

   Seventh, 
  the 
  colour 
  and 
  marking 
  in 
  the 
  two 
  species 
  are 
  

   different. 
  In 
  radula 
  the 
  ground-colour 
  of 
  the 
  dorsal 
  surface 
  

   is 
  of 
  a 
  light 
  cinnamon 
  brown, 
  with 
  regularly-placed 
  whitish 
  

   spots 
  upon 
  it 
  ; 
  while 
  circularis 
  is 
  usually 
  of 
  a 
  yellowish 
  colour, 
  

   with 
  only 
  the 
  central 
  circular 
  mark 
  on 
  each 
  " 
  wing." 
  In 
  

   addition 
  to 
  this, 
  it 
  has 
  sometimes 
  white 
  markings 
  similar 
  

   to 
  those 
  on 
  radula, 
  and 
  it 
  is 
  from 
  this 
  fact, 
  perhaps, 
  that 
  some 
  

   ichthyologists 
  believe 
  it 
  to 
  be 
  merely 
  the 
  young 
  of 
  radula, 
  

   and 
  that 
  the 
  large 
  circular 
  spots 
  disappear 
  with 
  age. 
  This, 
  

   however, 
  seems 
  to 
  me 
  untenable, 
  for 
  it 
  is 
  mature, 
  and 
  pro- 
  

   duces 
  its 
  kind 
  while 
  the 
  large 
  marks 
  are 
  still 
  upon 
  it. 
  Again, 
  

   these 
  same 
  white 
  markings, 
  similarly 
  arranged, 
  are 
  to 
  be 
  

   seen 
  as 
  frequently 
  upon 
  Baia 
  radiata, 
  a 
  form 
  which 
  no 
  one 
  

   would 
  think 
  of 
  confounding 
  with 
  either 
  of 
  the 
  species 
  under 
  

   consideration. 
  Eighth, 
  the 
  proportion 
  of 
  females 
  over 
  males 
  

   in 
  radula 
  is 
  extraordinary. 
  From 
  7th 
  May, 
  1892, 
  until 
  5th 
  

   July, 
  1895, 
  I 
  kept 
  a 
  daily 
  record 
  of 
  all 
  the 
  examples 
  of 
  

   radula 
  that 
  were 
  brought 
  into 
  Aberdeen 
  Market, 
  and 
  within 
  

   that 
  period 
  2865 
  females 
  stood 
  against 
  only 
  123 
  males 
  ; 
  

   whereas 
  in 
  the 
  case 
  of 
  circularis, 
  from 
  15th 
  August, 
  1894, 
  until 
  

   12th 
  July, 
  1895, 
  the 
  numbers 
  were 
  2237 
  females 
  and 
  2381 
  

   males, 
  showing 
  an 
  excess 
  of 
  144 
  males 
  over 
  females. 
  

  

  Now, 
  the 
  question 
  arises 
  (and 
  has 
  to 
  be 
  answered 
  by 
  

  

  