﻿PEGU 
  GROUP. 
  89 
  

  

  little 
  or 
  no 
  bearing" 
  on 
  the 
  question 
  of 
  these 
  Zen 
  fossils. 
  The 
  locality 
  is, 
  

   moreover 
  one, 
  where, 
  from 
  its 
  greater 
  proximity 
  to 
  the 
  edge 
  of 
  the 
  basin 
  

   of 
  deposition 
  of 
  the 
  Tertiary 
  sea 
  on 
  the 
  East 
  of 
  the 
  Pegu 
  Yomah, 
  we 
  

   should 
  expect, 
  if 
  any 
  such 
  existed 
  beneath, 
  to 
  find 
  older 
  beds 
  brought 
  

   up. 
  It 
  may 
  be 
  observed, 
  too, 
  that 
  beds 
  of 
  undoubtedly 
  Cretaceous 
  age 
  

   occur 
  on 
  the 
  Western 
  side 
  of 
  the 
  Arakan 
  Yomah, 
  if 
  not 
  within 
  the 
  

   actual 
  Irrawadi 
  basin; 
  so, 
  there 
  is 
  no 
  inherent 
  improbability 
  of 
  the 
  ex- 
  

   tension 
  of 
  these 
  cretaceous 
  beds 
  into 
  Eastern 
  Prome, 
  though 
  what 
  is 
  

   known 
  of 
  the 
  distribution 
  of 
  these 
  rocks 
  in 
  Arakan 
  does 
  not 
  seem 
  to 
  

   favour 
  the 
  idea, 
  but 
  this 
  will 
  be 
  treated 
  of 
  hereafter. 
  I 
  may 
  now 
  

   pass 
  to 
  the 
  description 
  of 
  what 
  I 
  have 
  termed 
  the 
  Nga-tha-mu 
  beds, 
  

   whose 
  exact 
  position 
  with 
  respect 
  to 
  the 
  Prome 
  group 
  is 
  doubtful. 
  

  

  Nga-tha-mu 
  heds. 
  — 
  A 
  remarkable 
  patch 
  of 
  beds, 
  somewhat 
  recall- 
  

   ing 
  in 
  general 
  appearance 
  the 
  Porebunder 
  beds 
  of 
  Kattiawar, 
  occurs 
  

   on 
  the 
  Arakan 
  coast, 
  but 
  is 
  nowhere 
  to 
  my 
  knowledge 
  seen 
  any- 
  

   where 
  else. 
  These 
  beds 
  embrace 
  Koranji 
  island 
  in 
  Lat. 
  16° 
  30' 
  50", 
  

   together 
  with 
  a 
  small 
  portion 
  of 
  the 
  mainland 
  near 
  the 
  village 
  of 
  

   Nga-tha-mu, 
  whence 
  their 
  name 
  is 
  taken. 
  The 
  most 
  characteristic 
  bed 
  

   is 
  a 
  calcareous 
  sandstone, 
  or 
  soft, 
  rather 
  earthy, 
  limestone 
  of 
  a 
  very 
  

   pale 
  brown 
  or 
  cream 
  color, 
  containing 
  four 
  species, 
  of 
  as 
  many 
  genera 
  

   of 
  echinoderms, 
  the 
  most 
  common 
  being 
  a 
  species, 
  of 
  Lobophora, 
  very 
  

   close 
  to 
  that 
  now 
  inhabiting 
  the 
  adjoining 
  coast, 
  and 
  a 
  species 
  of 
  

   Ec/iinolampas 
  (near 
  E. 
  affinis), 
  and 
  one 
  pelecypod, 
  a 
  rather 
  small 
  species 
  

   of 
  Amussium. 
  Koranji 
  island 
  consists 
  of 
  beds 
  of 
  thin 
  calcareous 
  sand- 
  

   stone, 
  having 
  a 
  high 
  dip, 
  West-by-north, 
  nearly; 
  to 
  which 
  it 
  may 
  

   partly 
  owe 
  its 
  protection 
  from 
  the 
  force 
  of 
  the 
  seas 
  which 
  break 
  

   violently 
  on 
  it, 
  but 
  are 
  received 
  by 
  the 
  sloping 
  beds 
  up 
  which 
  their 
  

   force 
  is 
  gradually 
  expended. 
  A 
  deposit 
  of 
  this 
  sort 
  must 
  have 
  had 
  

   a 
  far 
  greater 
  extension 
  formerly, 
  but 
  denudation 
  has, 
  save 
  at 
  this 
  

   one 
  spot, 
  removed 
  every 
  trace 
  of 
  it; 
  and 
  to 
  the 
  mechanical 
  advan- 
  

   tage 
  possessed 
  by 
  beds 
  dipping 
  seawards, 
  I 
  should 
  largely 
  attribute 
  

   m 
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