﻿ANATOMY 
  OF 
  THE 
  OYSTER. 
  

  

  THE 
  SHELL. 
  

  

  In 
  view 
  of 
  the 
  fact 
  that 
  the 
  structure 
  of 
  the 
  American 
  

   oyster 
  has 
  hitherto 
  excited 
  compai-atively 
  little 
  attention, 
  

   we 
  offer 
  here 
  tlie 
  results 
  of 
  investigations 
  made 
  upon 
  

   thirty-seven 
  specimens. 
  The 
  best 
  account 
  which 
  is 
  

   known 
  to 
  me, 
  and 
  one 
  accompanied 
  with 
  a 
  good 
  figure, 
  

   is 
  that 
  given 
  by 
  H. 
  James 
  Clark*, 
  and 
  which 
  anticipates 
  

   in 
  many 
  respects, 
  a 
  note 
  contributed 
  by 
  the 
  writer 
  to 
  

   the 
  American 
  Naturah'sf 
  foi- 
  September, 
  1880. 
  Another 
  

   admirable 
  account 
  of 
  the 
  structure 
  of 
  this 
  mollusc 
  has 
  

   been 
  given 
  by 
  Prof. 
  AV. 
  K. 
  Brooksf, 
  but 
  after 
  compari- 
  

   son, 
  I 
  find 
  that 
  my 
  observations 
  are 
  not 
  wholly 
  in 
  accord 
  

   with 
  the 
  accounts 
  of 
  either 
  of 
  tliese 
  careful 
  observers. 
  

  

  In 
  Fig. 
  I, 
  I 
  have 
  attempted 
  to 
  represent 
  in 
  a 
  somewhat 
  

   diagrammatic 
  manner 
  the 
  structure 
  of 
  the 
  animal 
  under 
  

   consideration, 
  with 
  indications 
  of 
  some 
  of 
  its 
  physiologi- 
  

   cal 
  or 
  animal 
  processes, 
  such 
  as 
  the 
  inhalation 
  and 
  exha- 
  

   lation 
  of 
  water 
  for 
  breathing 
  purposes, 
  and 
  the 
  manner 
  

   in 
  which 
  the 
  food 
  is 
  carried 
  to 
  the 
  mouth 
  to 
  be 
  swallowed. 
  

  

  The 
  oyster 
  always 
  presents 
  a 
  definite 
  right 
  and 
  left 
  

   side, 
  and 
  the 
  two 
  shells 
  or 
  valves 
  which 
  enclose 
  the 
  

   animal, 
  always 
  differ 
  in 
  that 
  the 
  left 
  one 
  is 
  more 
  deeply 
  

   concave 
  or 
  hollowed 
  out 
  than 
  the 
  right, 
  which 
  is 
  nearly 
  

   flat. 
  In 
  the 
  natural 
  beds 
  the 
  left 
  valve 
  is 
  usually, 
  if 
  not 
  

   always 
  undermost, 
  but 
  in 
  the 
  crowded 
  banks 
  the 
  animal 
  

   usually 
  assumes 
  a 
  vertical 
  position, 
  a 
  condition 
  which 
  

   does 
  not, 
  however, 
  affect 
  this 
  unlikeness 
  of 
  the 
  valves. 
  

   In 
  \\\Q 
  figure, 
  the 
  left 
  valve 
  has 
  been 
  removed, 
  the 
  ani- 
  

   mal 
  of 
  the 
  oyster 
  is 
  shown 
  lying 
  in 
  the 
  more 
  shallow 
  

   right. 
  The 
  head 
  end 
  of 
  the 
  animal 
  lies 
  close 
  against 
  the 
  

  

  •Mind 
  in 
  Nature. 
  New 
  York, 
  1865. 
  pp. 
  199 
  — 
  203. 
  

  

  tReport 
  of 
  the 
  Maryland 
  Commissioners 
  of 
  Fisheries, 
  1880. 
  pp. 
  5 
  — 
  10. 
  

  

  