﻿'554 
  Geological 
  Society. 
  

  

  -the 
  south 
  and 
  to 
  the 
  north 
  of 
  the 
  island, 
  aud 
  is 
  connected 
  by 
  

   another 
  ridge 
  with 
  the 
  Martinique 
  mass. 
  Its 
  hydrographic 
  features 
  

   are 
  best 
  understood 
  when 
  studying 
  the 
  question 
  of 
  the 
  general 
  

   relationship 
  of 
  the 
  islands. 
  

  

  Trinidad 
  is 
  part 
  of 
  the 
  South 
  American 
  continent, 
  being 
  on 
  the 
  

   subcoastal 
  shelf 
  which 
  extends 
  much 
  farther 
  seaward. 
  

  

  The 
  Scotland 
  Sands 
  and 
  the 
  deep 
  Oceanic 
  Series 
  of 
  Barbados 
  

   have 
  been 
  comprehensively 
  studied 
  by 
  others. 
  The 
  Oceanic 
  Series 
  

   is 
  here 
  shown 
  to 
  be 
  no 
  newer 
  than 
  the 
  Eocene 
  Period, 
  and 
  the 
  

   Scotland 
  Series 
  is 
  supposed 
  to 
  date 
  back 
  to 
  the 
  beginning 
  of 
  the 
  

   Tertiary 
  or 
  even 
  to 
  an 
  older 
  epoch. 
  The 
  ' 
  Raised 
  Coral-Eeefs 
  ' 
  are 
  

   differentiated 
  into 
  three 
  formations, 
  all 
  of 
  white 
  limestone 
  or 
  marl. 
  

   The 
  oldest 
  beds 
  are 
  all 
  tilted 
  to 
  considerable 
  angles. 
  They 
  contain 
  

   an 
  Oligocene 
  fauna. 
  Their 
  surfaces 
  are 
  eroded 
  into 
  rounded 
  forms, 
  

   showing 
  that 
  the 
  topographic 
  feature 
  was 
  completed 
  at 
  a 
  low 
  

   elevation 
  above 
  the 
  base-level 
  of 
  erosion. 
  As 
  no 
  other 
  Tertiary 
  

   formation 
  occurs 
  until 
  the 
  close 
  of 
  the 
  Pliocene, 
  it 
  is 
  inferred 
  that 
  

   the 
  region 
  was 
  a 
  land-surface 
  throughout 
  the 
  long 
  Miocene-Pliocene 
  

   Period. 
  This 
  limestone 
  is 
  the 
  equivalent 
  of 
  the 
  Antigua 
  Formation. 
  

   In 
  the 
  hollows 
  of 
  its 
  surface 
  occur 
  the 
  remains 
  of 
  a 
  mechanical 
  

   limestone 
  (the 
  Ragged 
  Point 
  Series), 
  which 
  has 
  been 
  mostly 
  

   carried 
  away 
  by 
  subsequent 
  denudation. 
  It 
  lies 
  in 
  a 
  horizontal 
  

   position. 
  Newer 
  still 
  is 
  the 
  Bath 
  Series, 
  or 
  raised 
  coral-reefs, 
  

   with 
  a 
  fauna 
  still 
  living. 
  However, 
  it 
  is 
  an 
  old 
  Pleistocene 
  forma- 
  

   tion, 
  and 
  its 
  surface 
  is 
  very 
  much 
  denuded. 
  Some 
  of 
  the 
  newer 
  

   fossiliferous 
  beds 
  may 
  represent 
  even 
  another 
  distinct 
  Pleistocene 
  

   epoch. 
  The 
  greatest 
  elevation 
  and 
  denudation 
  appears 
  to 
  have 
  been 
  

   in 
  the 
  early 
  Pleistocene 
  days. 
  The 
  terraces 
  occur 
  in 
  Barbados 
  at 
  

   much 
  higher 
  elevations 
  than 
  in 
  the 
  other 
  islands, 
  as 
  this 
  district 
  does 
  

   not 
  appear 
  to 
  have 
  undergone 
  so 
  great 
  an 
  amount 
  of 
  recent 
  sub- 
  

   sidence 
  as 
  that 
  which 
  carried 
  down 
  the 
  surfaces, 
  with 
  little 
  canons 
  

   and 
  channels, 
  below 
  sea-level, 
  adjacent 
  to 
  the 
  other 
  islands. 
  The 
  

   local 
  features 
  of 
  Barbados 
  extend 
  our 
  knowledge 
  of 
  the 
  history 
  of 
  

   the 
  whole 
  chain 
  of 
  islands, 
  besides 
  agreeing 
  with 
  the 
  phenomena 
  

   found 
  elsewhere. 
  

  

  Trinidad 
  has 
  more 
  continental 
  features 
  than 
  the 
  other 
  islands. 
  

   Its 
  surface- 
  topography 
  has 
  been 
  found 
  to 
  owe 
  its 
  origin 
  to 
  the 
  

   erosion 
  -features 
  of 
  the 
  Miocene-Pliocene 
  Period, 
  which 
  have 
  been 
  

   covered 
  by 
  only 
  thin 
  mantles 
  as 
  in 
  Barbados, 
  so 
  that 
  its 
  life-history 
  

   falls 
  into 
  harmony 
  with 
  that 
  of 
  the 
  other 
  islands. 
  In 
  its 
  older 
  beds 
  

   it 
  has 
  the 
  deep 
  oceanic 
  oozes 
  as 
  in 
  Barbados. 
  No 
  volcanic 
  

   phenomena 
  have 
  been 
  added 
  to 
  the 
  features 
  of 
  these 
  islands. 
  

  

  This 
  paper 
  is 
  the 
  last 
  of 
  a 
  descriptive 
  series, 
  but 
  a 
  clearer 
  under- 
  

   standing 
  would 
  be 
  obtained 
  by 
  bringing 
  together 
  the 
  results, 
  showing 
  

   the 
  variations 
  and 
  developments 
  in 
  different 
  localities. 
  

  

  