﻿INTRODUCTION. 
  Panama 
  Shells. 
  247 
  

  

  this 
  extreme 
  low 
  water 
  mark, 
  where 
  the 
  air 
  will 
  hut 
  slightly 
  

   reach 
  the 
  animal 
  every 
  fortnight, 
  and 
  that 
  of 
  a 
  few 
  feet 
  high- 
  

   er, 
  whence 
  the 
  water 
  wholly 
  recedes 
  twice 
  every 
  day. 
  

  

  Having 
  an 
  opportunity 
  of 
  shipping 
  the 
  collections, 
  which 
  

   filled 
  eight 
  cases, 
  we 
  wrote 
  the 
  bills 
  of 
  lading, 
  Jan. 
  3, 
  1851, 
  

   and 
  the 
  next 
  morning 
  left 
  Panama 
  for 
  Chagres 
  and 
  Jamaica. 
  

   It 
  was 
  not 
  until 
  Aug. 
  14 
  that 
  the 
  cases 
  arrived 
  at 
  their 
  des- 
  

   tination. 
  After 
  assorting 
  the 
  shells, 
  we 
  find 
  38.920 
  speci- 
  

   mens 
  of 
  376 
  species 
  of 
  Gasteropoda, 
  2.860 
  specimens 
  of 
  139 
  

   species 
  of 
  Acephala, 
  and 
  50 
  specimens 
  of 
  1 
  species 
  of 
  Brach- 
  

   iopoda 
  : 
  total, 
  41.830 
  specimens 
  of 
  516 
  species 
  of 
  Mollusks. 
  

   The 
  number 
  of 
  specimens 
  of 
  each 
  species 
  is 
  mentioned 
  in 
  the 
  

   following 
  pages. 
  It 
  is 
  scarcely 
  necessary 
  to 
  add 
  that 
  we 
  have 
  

   stated 
  the 
  total 
  number 
  of 
  individuals, 
  to 
  give 
  approximately 
  

   an 
  idea 
  of 
  the 
  relative 
  abundance 
  of 
  the 
  species 
  at 
  the 
  time 
  

   and 
  places 
  mentioned, 
  and 
  not 
  of 
  such 
  specimens 
  as 
  amateurs 
  

   would 
  pronounce 
  ' 
  good 
  shells.' 
  

  

  In 
  the 
  following 
  catalogue 
  our 
  principal 
  object, 
  after 
  the 
  

   enumeration 
  of 
  the 
  species, 
  has 
  been 
  to 
  collect 
  the 
  statement 
  

   of 
  various 
  writers 
  concerning 
  the 
  habitats 
  and 
  stations 
  of 
  the 
  

   species. 
  "Where 
  two 
  names 
  of 
  persons 
  follow 
  the 
  habitat 
  or 
  

   station, 
  the 
  first 
  is 
  usually 
  that 
  of 
  the 
  person 
  who 
  collected 
  the 
  

   species, 
  and 
  is 
  followed 
  by 
  an 
  exclamation 
  mark 
  ! 
  The 
  second 
  

   name 
  is 
  that 
  of 
  the 
  author 
  who 
  is 
  quoted. 
  The 
  (I) 
  after 
  a 
  

   single 
  name 
  indicates 
  that 
  the 
  author 
  was 
  also 
  the 
  collector 
  ', 
  

   but 
  the 
  absence 
  of 
  this 
  mark 
  indicates 
  that 
  the 
  testimony 
  is 
  

   not 
  original, 
  whether 
  one 
  or 
  more 
  names 
  are 
  cited. 
  

  

  It 
  will 
  be 
  seen 
  that 
  for 
  a 
  knowledge 
  of 
  the 
  stations 
  we 
  

   are 
  chiefly 
  indebted 
  to 
  Mr. 
  Cuming. 
  

  

  In 
  appending 
  synonymy, 
  we 
  have 
  quoted 
  nothing. 
  The 
  

   references 
  have 
  been 
  made 
  chiefly 
  as 
  vouchers 
  for 
  the 
  accu- 
  

   racy 
  of 
  the 
  names 
  of 
  the 
  species, 
  and 
  as 
  means 
  of 
  detecting 
  

   errors. 
  A 
  subordinate 
  object 
  has 
  been 
  the 
  convenience 
  of 
  

   those 
  friends 
  among 
  whom 
  the 
  duplicate 
  specimens 
  may 
  be 
  

  

  