﻿246 
  Panama 
  Shells. 
  introduction. 
  

  

  beneath 
  stones. 
  Many 
  such 
  heaps 
  were 
  collected 
  in 
  the 
  mass, 
  

   to 
  be 
  culled 
  over 
  in 
  the 
  leisure 
  of 
  home. 
  To 
  this 
  source 
  we 
  

   are 
  wholly 
  indebted 
  for 
  many 
  species 
  of 
  shells, 
  not 
  a 
  few 
  of 
  

   which 
  are 
  in 
  such 
  a 
  good 
  state 
  of 
  preservation 
  that 
  we 
  have 
  

   to 
  regret 
  only 
  the 
  impossibility 
  of 
  describing 
  the 
  station 
  of 
  

   these 
  species. 
  

  

  In 
  these 
  Pacific 
  waters, 
  not 
  much 
  addition 
  to 
  the 
  stores 
  

   of 
  the 
  collector 
  can 
  be 
  made 
  from 
  the 
  drift 
  shelis. 
  Yet 
  the 
  

   flow 
  of 
  the 
  tides 
  and 
  a 
  moderate 
  surf 
  brought 
  several 
  species 
  

   within 
  reach. 
  Several 
  of 
  the 
  bivalves, 
  which 
  live 
  buried 
  in 
  

   sand, 
  and 
  whose 
  station 
  eluded 
  discovery, 
  were 
  thus 
  obtained. 
  

   But 
  especially 
  were 
  we 
  indebted 
  to 
  this 
  source 
  for 
  the 
  ex- 
  

   tremely 
  minute 
  species, 
  several 
  of 
  which 
  were 
  not 
  recognised 
  

   until 
  the 
  conchiferous 
  rubbish 
  and 
  sand 
  had 
  been 
  assorted 
  

   with 
  sieves 
  and 
  then 
  carefully 
  examined. 
  

  

  From 
  the 
  natives 
  we 
  obtained 
  but 
  little 
  aid. 
  The 
  shells 
  

   of 
  a 
  few 
  edible 
  species 
  vveie 
  taken 
  from 
  heaps 
  near 
  their 
  huts. 
  

   A 
  few 
  species 
  were 
  obtained 
  in 
  a 
  fruit 
  shanty, 
  which 
  was 
  

   kept 
  by 
  an 
  American 
  on 
  the 
  Plaza. 
  The 
  habitat 
  of 
  most 
  of 
  

   these 
  was 
  verified 
  by 
  subsequently 
  finding 
  them 
  on 
  the 
  shores. 
  

   That 
  of 
  four 
  or 
  five 
  species 
  was 
  satisfactorily 
  inferred, 
  inde- 
  

   pently 
  of 
  the 
  testimony, 
  from 
  the 
  fact 
  that 
  no 
  shells 
  known 
  

   to 
  inhabit 
  other 
  regions 
  were 
  seen 
  in 
  the 
  shanty, 
  and 
  that 
  

   these 
  species 
  have 
  been 
  found 
  by 
  others 
  in 
  the 
  same 
  zoologi- 
  

   cal 
  province. 
  Those 
  which 
  were 
  thus 
  obtained 
  are 
  mentioned 
  

   accordingly 
  in 
  the 
  statement 
  of 
  habitat. 
  

  

  In 
  a 
  few 
  instances 
  it 
  will 
  be 
  noticed 
  that 
  our 
  account 
  of 
  

   the 
  station 
  differs 
  somewhat 
  from 
  Mr. 
  Cuming's. 
  This 
  is 
  due 
  

   chiefly 
  to 
  the 
  considerable 
  range 
  which 
  some 
  species 
  have, 
  

   especially 
  with 
  different 
  circumstances 
  of 
  place. 
  Thus 
  sever- 
  

   al 
  of 
  the 
  species, 
  which 
  we 
  found 
  at 
  the 
  low 
  water 
  mark 
  of 
  

   spring 
  tides, 
  were 
  obtained 
  by 
  Mr. 
  Cuming 
  at 
  the 
  depth 
  of 
  

   fifteen 
  or 
  more 
  fathoms. 
  The 
  difference 
  between 
  such 
  sta- 
  

   tions 
  is 
  obviously 
  of 
  much 
  less 
  importance 
  than 
  that 
  between 
  

  

  