﻿GEOLOGY. 
  269 
  

  

  PALAEONTOLOGY. 
  

  

  Palaeontology 
  is 
  that 
  branch 
  of 
  natural 
  history 
  by 
  

   which 
  we 
  gain 
  a 
  definite 
  knowledge 
  of 
  organic 
  remains, 
  

   or 
  of 
  the 
  fossil 
  and 
  extinct 
  animals 
  and 
  plants 
  which 
  

   have 
  been 
  aptly 
  termed 
  the 
  medals 
  of 
  creation, 
  and 
  the 
  

   embalmed 
  memorials 
  of 
  a 
  former 
  world. 
  

  

  It 
  furnishes 
  a 
  certain 
  clue 
  and 
  guide 
  in 
  our 
  geological 
  

   researches, 
  and 
  enables 
  us 
  to 
  identify 
  the 
  different 
  forma- 
  

   tions 
  in 
  very 
  distant 
  localities 
  when 
  the 
  distinctions 
  

   founded 
  solely 
  on 
  mineral 
  characters 
  would 
  fail. 
  

  

  The 
  discovery 
  was 
  made, 
  about 
  half 
  a 
  century 
  since, 
  

   by 
  William 
  Smith, 
  a 
  land 
  surveyor, 
  and 
  now 
  recognized 
  

   as 
  " 
  the 
  father 
  of 
  English 
  geology," 
  that 
  certain 
  groups 
  

   of 
  fossils 
  were 
  peculiar 
  to 
  certain 
  strata 
  ; 
  a 
  knowledge 
  

   which 
  has 
  since 
  been 
  improved 
  by 
  Sir 
  Charles 
  Lyell, 
  in 
  

   his 
  division 
  of 
  the 
  tertiary 
  strata, 
  as 
  has 
  before 
  been 
  

   stated. 
  In 
  this 
  division, 
  the 
  testacea 
  or 
  shells, 
  found 
  to 
  

   exist 
  in 
  greatest 
  abundance 
  and 
  variety, 
  and 
  of 
  wider 
  

   and 
  more 
  general 
  distribution, 
  have 
  been 
  adopted, 
  to 
  the 
  

   exclusion 
  of 
  the 
  remains 
  of 
  plants 
  and 
  vertebrated 
  ani- 
  

   mals, 
  which 
  are 
  comparatively 
  of 
  too 
  few 
  species 
  and 
  are 
  

   confined 
  to 
  fewer 
  localities. 
  

  

  More 
  than 
  three 
  thousand 
  species 
  of 
  fossil 
  shells 
  have 
  

   been 
  ascertained. 
  Of 
  these, 
  about 
  eight 
  hundred 
  perhaps 
  

   belong 
  to 
  the 
  pliocene, 
  one 
  thousand 
  to 
  the 
  miocene, 
  and 
  

   twelve 
  hundred 
  to 
  the 
  eocene 
  divisions 
  of 
  the 
  tertiary 
  ; 
  

   and, 
  although 
  some 
  species 
  may 
  be 
  common 
  to 
  all, 
  or 
  

   run 
  into 
  the 
  other 
  divisions, 
  yet 
  a 
  large 
  proportion 
  of 
  

   them 
  may 
  be 
  regarded 
  as 
  the 
  exclusive 
  and 
  characteristic 
  

   fossils 
  of 
  each. 
  

  

  