﻿Agassiz 
  — 
  Exploitations 
  of 
  the 
  " 
  Albatross" 
  115 
  

  

  towards 
  the 
  lagoon, 
  killing 
  the 
  pandanus 
  and 
  whatever 
  vegeta- 
  

   tion 
  there 
  is 
  growing 
  on 
  the 
  land 
  rim 
  of 
  the 
  lagoon. 
  The 
  

   dimes 
  have 
  probably 
  tilled 
  also 
  a 
  second 
  entrance 
  to 
  the 
  lagoon 
  

   indicated 
  now 
  only 
  by 
  a 
  somewhat 
  lower 
  level 
  of 
  the 
  land 
  rim. 
  

   Mr. 
  Moore 
  and 
  Mr. 
  Townsend, 
  who 
  went 
  ashore 
  at 
  Pinaki, 
  

   report 
  that 
  the 
  lagoon 
  is 
  not 
  more 
  than 
  3 
  fathoms 
  deep 
  ; 
  they 
  

   could 
  wade 
  over 
  the 
  greater 
  part 
  of 
  it, 
  Mr. 
  Alexander 
  counted 
  

   no 
  less 
  than 
  116 
  islets 
  in 
  this 
  small 
  lagoon 
  — 
  less 
  than 
  a 
  mile 
  in 
  

   diameter 
  — 
  islets 
  formed 
  of 
  masses 
  of 
  dead 
  Tridacna 
  shells 
  

   thrown 
  up 
  on 
  ledge 
  rock, 
  on 
  the 
  slopes 
  of 
  which 
  grew 
  madre- 
  

   pores. 
  The 
  bottom 
  of 
  the 
  lagoon 
  is 
  covered 
  by 
  Tridacna 
  and 
  

   masses 
  of 
  a 
  species 
  of 
  Area 
  live 
  near 
  the 
  edge 
  ; 
  the 
  interven- 
  

   ing 
  spaces 
  being 
  filled 
  with 
  nullipores. 
  The 
  entrance 
  to 
  the 
  

   lagoon 
  is 
  perhaps 
  150 
  feet 
  wide, 
  and 
  there 
  is 
  a 
  cut 
  through 
  the 
  

   beach 
  rock 
  covering 
  the 
  old 
  ledge 
  giving 
  access 
  to 
  the 
  sea 
  into 
  

   the 
  lagoon 
  at 
  certain 
  stages 
  of 
  the 
  tide. 
  The 
  water 
  in 
  the 
  

   lagoon 
  is 
  quite 
  warm. 
  

  

  At 
  Pinaki, 
  as 
  at 
  other 
  atolls 
  and 
  islets 
  to 
  the 
  eastward, 
  there 
  

   are 
  fewer 
  cocoanuts 
  than 
  on 
  the 
  westward 
  atolls, 
  and 
  the 
  vege- 
  

   tation 
  consists 
  in 
  great 
  part 
  of 
  pandanus 
  and 
  puteau 
  trees 
  and 
  

   the 
  usual 
  coral 
  reef 
  vegetation 
  of 
  the 
  Paumotus 
  and 
  Fijis. 
  

  

  The 
  only 
  atoll 
  we 
  have 
  seen, 
  the 
  lagoon 
  of 
  which 
  is 
  entirely 
  

   shut 
  off 
  from 
  the 
  sea, 
  is 
  Niau. 
  In 
  this 
  case 
  the 
  old 
  ledge 
  form- 
  

   ing 
  the 
  rim 
  of 
  the 
  land, 
  which 
  surrounds 
  the 
  nearly 
  circular 
  

   lagoon, 
  is 
  about 
  a 
  third 
  of 
  a 
  mile 
  in 
  width 
  and 
  sufficiently 
  high, 
  

   15 
  to 
  20 
  feet, 
  to 
  prevent 
  any 
  sea 
  from 
  having 
  access 
  to 
  it 
  

   except 
  in 
  case 
  of 
  a 
  cyclone, 
  as 
  that 
  of 
  1878, 
  when 
  the 
  sea 
  

   washed 
  into 
  the 
  lagoon. 
  The 
  lagoon 
  is 
  shallow, 
  of 
  an 
  average 
  

   depth 
  of 
  about 
  3 
  fathoms, 
  the 
  deeper 
  parts 
  perhaps 
  5. 
  The 
  

   water 
  is 
  brackish, 
  of 
  a 
  density 
  of 
  1*0216 
  at 
  28° 
  C. 
  There 
  

   are 
  no 
  corals 
  living 
  in 
  it, 
  but 
  a 
  species 
  of 
  mullet 
  is 
  found, 
  as 
  

   well 
  as 
  many 
  marine 
  shells, 
  which, 
  like 
  those 
  in 
  the 
  lagoons 
  of 
  

   San 
  Salvador, 
  in 
  the 
  Bahamas, 
  are 
  of 
  diminutive 
  size 
  com- 
  

   pared 
  to 
  their 
  representatives 
  living 
  outside. 
  The 
  floor 
  of 
  the 
  

   lagoon 
  is 
  covered 
  with 
  algge. 
  The 
  lagoon 
  has 
  probably 
  a 
  slight 
  

   connection 
  with 
  the 
  sea, 
  the 
  water 
  percolating 
  through 
  the 
  

   limestone 
  ring 
  separating 
  it 
  from 
  the 
  outer 
  reef 
  flat. 
  It 
  is 
  

   very 
  difficult 
  in 
  this 
  case 
  to 
  decide 
  whether 
  this 
  lagoon 
  has 
  

   been 
  gradually 
  filled 
  up 
  after 
  elevation, 
  or 
  whether 
  it 
  is 
  merely 
  

   a 
  sink 
  on 
  a 
  more 
  or 
  less 
  uneven 
  limestone 
  surface. 
  

  

  Dana, 
  and 
  other 
  writers 
  on 
  coral 
  reefs, 
  mention 
  a 
  great 
  num- 
  

   ber 
  of 
  lagoons 
  as 
  being 
  absolutely 
  shut 
  off 
  from 
  the 
  sea, 
  I 
  

   take 
  it 
  these 
  statements 
  are 
  due 
  to 
  their 
  descriptions 
  being 
  

   taken 
  from 
  charts, 
  many 
  of 
  which, 
  as 
  in 
  the 
  case 
  of 
  the 
  Pau- 
  

   motus, 
  are 
  very 
  defective. 
  For 
  nothing 
  is 
  easier 
  than 
  to 
  pass 
  

   at 
  a 
  short 
  distance 
  by 
  the 
  wide 
  and 
  narrow 
  cuts 
  which 
  give 
  in 
  

   so 
  many 
  cases 
  the 
  freest 
  access 
  to 
  the 
  sea 
  to 
  the 
  interior 
  of 
  the 
  

  

  