﻿INTRODUCTION. 
  

  

  Panama 
  Shells. 
  243 
  

  

  the 
  California 
  travel. 
  Littoral 
  explorations 
  however, 
  produce 
  

   a 
  greater 
  amount 
  of 
  results 
  in 
  a 
  short 
  time. 
  

  

  It 
  has 
  become 
  so 
  fashionable 
  to 
  undervalue 
  a 
  knowledge 
  

   of 
  the 
  shells 
  of 
  Mollusca, 
  because 
  the 
  shell 
  is 
  only 
  a 
  part 
  of 
  

   the 
  animal, 
  that 
  we 
  shall 
  probably 
  be 
  censured 
  for 
  having 
  neg- 
  

   lected 
  to 
  observe 
  the 
  soft 
  parts. 
  But 
  non 
  omnes 
  omnia 
  pos- 
  

   sumus, 
  especially 
  with 
  only 
  six 
  weeks 
  time. 
  It 
  will 
  not 
  be 
  

   denied 
  that 
  the 
  existence 
  of 
  the 
  species 
  is 
  sufficiently 
  proved 
  

   by 
  collecting 
  the 
  shells, 
  nor 
  that 
  their 
  geographical 
  distribu- 
  

   tion 
  may 
  be 
  learned, 
  when 
  we 
  ascertain 
  where 
  they 
  exist, 
  — 
  

   nor 
  that 
  habits 
  of 
  station 
  may 
  be 
  learned 
  without 
  dissection, 
  

   although 
  this 
  is 
  indispensable 
  for 
  some 
  objects, 
  — 
  nor 
  that 
  the 
  

   recondite 
  questions 
  on 
  the 
  origin 
  of 
  the 
  species 
  are 
  intimately 
  

   connected 
  with 
  the 
  facts 
  of 
  distribution 
  and 
  station, 
  — 
  nor 
  

   even 
  that 
  the 
  number 
  of 
  species 
  in 
  a 
  given 
  region 
  and 
  the 
  

   abundance 
  or 
  scarcity 
  of 
  individuals 
  are 
  interesting 
  features 
  

   in 
  the 
  plan 
  of 
  creation. 
  In 
  short, 
  it 
  will 
  not 
  be 
  denied 
  that 
  

   the 
  sum 
  total 
  of 
  Zoology 
  consists 
  of 
  parts, 
  and 
  that 
  the 
  per- 
  

   fection 
  of 
  the 
  whole 
  may 
  be 
  better 
  secured 
  by 
  a 
  division 
  of 
  

   labor. 
  We 
  hope 
  therefore, 
  that 
  the 
  following 
  results, 
  not- 
  

   withstanding 
  the 
  magnitude 
  of 
  the 
  deficiencies, 
  will 
  be 
  re- 
  

   garded 
  as 
  somewhat 
  better 
  than 
  the 
  only 
  alternative 
  before 
  us, 
  

   — 
  that 
  of 
  the 
  stay-at-home 
  collectors. 
  

  

  The 
  situation 
  of 
  Panama 
  is 
  eminently 
  favorable 
  for 
  the 
  

   collection 
  of 
  shells. 
  At 
  the 
  head 
  of 
  an 
  extensive 
  bay, 
  whose 
  

   waters 
  w^ell 
  merit 
  the 
  appellation 
  of 
  Pacific, 
  it 
  stands 
  also 
  at 
  

   the 
  head 
  of 
  a 
  reef, 
  which 
  furnishes 
  a 
  great 
  variety 
  of 
  station 
  

   for 
  the 
  mollusks. 
  Our 
  hotel 
  was 
  within 
  a 
  minute's 
  walk 
  of 
  

   this 
  reef. 
  In 
  front 
  of 
  the 
  city, 
  the 
  reef 
  consists 
  of 
  ledges 
  of 
  

   trachytio 
  rocks, 
  with 
  flat 
  and 
  concave 
  surfaces, 
  with 
  gently 
  

   sloping, 
  precipitous, 
  or 
  shelving 
  sides 
  : 
  in 
  other 
  parts 
  exten- 
  

   sive 
  tracts 
  are 
  covered 
  with 
  loose 
  fragments 
  of 
  rock, 
  the 
  diffe- 
  

   rent 
  sizes 
  of 
  which, 
  and 
  the 
  different 
  degrees 
  in 
  which 
  they 
  

   are 
  buried 
  in 
  sand, 
  or 
  in 
  which 
  they 
  have 
  open 
  spaces 
  be- 
  

  

  