﻿A. 
  Agassis 
  — 
  Explorations 
  of 
  the 
  " 
  Albatross." 
  39 
  

  

  could 
  be 
  seen 
  over 
  the 
  floor 
  of 
  the 
  Avatom 
  passage 
  down 
  to 
  

   from 
  9 
  to 
  10 
  fathoms; 
  and 
  on 
  the 
  sea 
  face 
  Pocillopores 
  

   covered 
  the 
  outer 
  edge 
  of 
  the 
  shore 
  platform. 
  This 
  platform 
  

   is 
  from 
  200 
  to 
  250 
  feet 
  wide, 
  and 
  was 
  formed 
  by 
  the 
  planing 
  

   off 
  of 
  the 
  seaward 
  extension 
  of 
  the 
  ledge 
  cropping 
  out 
  in 
  the 
  

   cuts. 
  

  

  It 
  became 
  very 
  evident, 
  after 
  we 
  had 
  examined 
  the 
  south 
  

   shore 
  of 
  the 
  lagoon, 
  that 
  the 
  ledge 
  underlying 
  the 
  north 
  shore 
  

   is 
  the 
  remnant 
  of 
  the 
  bed, 
  an 
  old 
  Tertiary 
  coralliferous 
  lime- 
  

   stone 
  which 
  at 
  one 
  time 
  covered 
  the 
  greater 
  part 
  of 
  the 
  area 
  

   of 
  the 
  lagoon, 
  portions 
  of 
  which 
  may 
  have 
  been 
  elevated 
  to 
  a 
  

   considerable 
  height. 
  This 
  limestone 
  was 
  gradually 
  denuded 
  

   and 
  eroded 
  to 
  the 
  level 
  of 
  the 
  sea. 
  Passages 
  were 
  formed 
  on 
  

   its 
  outside 
  edge, 
  allowing 
  the 
  sea 
  access 
  to 
  the 
  inner 
  parts 
  of 
  the 
  

   lagoon. 
  This 
  began 
  to 
  cut 
  away 
  the 
  inner 
  portions 
  of 
  the 
  

   elevated 
  limestone, 
  forming 
  large 
  sounds, 
  as 
  in 
  the 
  case 
  of 
  

   Fiji 
  atolls, 
  and 
  leaving 
  Anally 
  on 
  the 
  south 
  side 
  only 
  a 
  flat 
  

   strip 
  of 
  perhaps 
  2,500 
  to 
  3,000 
  feet 
  width 
  which 
  has 
  gradually 
  

   been 
  further 
  eroded 
  on 
  the 
  lagoon 
  side, 
  and 
  also 
  on 
  the 
  sea 
  

   face 
  to 
  leave 
  only 
  a 
  narrow 
  strip 
  of 
  land 
  about 
  1,000 
  feet 
  in 
  

   width 
  and 
  perhaps 
  10 
  to 
  14 
  feet 
  in 
  height, 
  the 
  material 
  for 
  

   this 
  land 
  having 
  come 
  from 
  the 
  disintegration 
  of 
  the 
  ledge 
  of 
  

   Tertiary 
  limestone, 
  both 
  on 
  the 
  sea 
  face 
  and 
  the 
  lagoon 
  side. 
  

  

  There 
  exist 
  in 
  the 
  lagoon 
  a 
  number 
  of 
  small 
  islets 
  which 
  

   also 
  consist 
  of 
  this 
  same 
  Tertiary 
  limestone 
  in 
  process 
  of 
  disin- 
  

   tegration 
  and 
  transformation 
  to 
  coral 
  sand 
  islets. 
  They 
  are. 
  

   the 
  islets 
  at 
  the 
  lagoon 
  side 
  of 
  both 
  Avatoru 
  and 
  Tiputa 
  

   Passes, 
  the 
  two 
  islets 
  which 
  we 
  found 
  along 
  our 
  line 
  of 
  

   soundings, 
  the 
  one 
  about 
  4^ 
  miles 
  from 
  the 
  north 
  side 
  of 
  the 
  

   lagoon, 
  and 
  the 
  other 
  about 
  the 
  same 
  distance 
  from 
  the 
  south 
  

   shore. 
  I 
  am 
  told 
  that 
  the 
  eastern 
  extremity 
  of 
  the 
  lagoon 
  is 
  

   tilled 
  with 
  islets 
  and 
  heads 
  consisting 
  of 
  the 
  same 
  limestone 
  

   rock 
  so 
  characteristic 
  of 
  the 
  north 
  and 
  south 
  shores 
  of 
  the 
  

   lagoon. 
  

  

  The 
  underlying 
  ledge 
  is 
  not 
  the 
  remnant 
  of 
  a 
  modern 
  reef 
  ; 
  

   its 
  character 
  is 
  identical 
  with 
  that 
  of 
  the 
  elevated 
  limestones 
  

   of 
  Fiji, 
  which 
  are 
  of 
  Tertiary 
  age, 
  and 
  the 
  rock 
  is 
  in 
  every 
  

   respect 
  the 
  same 
  as 
  that 
  I 
  observed 
  on 
  many 
  of 
  the 
  elevated 
  

   islands 
  of 
  Fiji. 
  The 
  atoll 
  of 
  Pairoa 
  is 
  in 
  a 
  stage 
  of 
  denudation 
  

   and 
  erosion 
  very 
  similar 
  to 
  that 
  of 
  Ngele 
  Levu, 
  in 
  Fiji, 
  only 
  in 
  

   Xgele 
  Levu 
  the 
  elevated 
  limestone 
  attains 
  a 
  height 
  of 
  about 
  

   60 
  feet. 
  Our 
  visit 
  to 
  the 
  south 
  shore 
  of 
  the 
  lagoon, 
  both 
  on 
  

   the 
  lagoon 
  side 
  and 
  on 
  the 
  sea 
  face, 
  left 
  us 
  no 
  donbt 
  regarding 
  

   the 
  character 
  of 
  the 
  underlying 
  ledge 
  of 
  the 
  north 
  shore. 
  As 
  

   soon 
  as 
  the 
  south 
  shore 
  was 
  sufficiently 
  near, 
  as 
  seen 
  from 
  the 
  

   lagoon 
  side, 
  for 
  us 
  to 
  distinguish 
  its 
  character, 
  we 
  could 
  see 
  

   that 
  the 
  entire 
  shore 
  line 
  was 
  formed 
  of 
  a 
  hiirh 
  ledsre 
  of 
  lime- 
  

  

  