﻿HUDSON 
  RIVER 
  BEDS 
  NEAR 
  ALBANY 
  495 
  

  

  But 
  Hall 
  soon 
  discovered 
  his 
  error 
  in 
  regard 
  to 
  this 
  correla- 
  

   tion 
  with 
  the 
  Point 
  Levis 
  graptolites 
  and 
  protested 
  against 
  the 
  

   inclusion 
  of 
  the 
  Hudson 
  river 
  graptolites 
  with 
  those 
  of 
  the 
  slates 
  

   of 
  Point 
  Levis; 
  as 
  a 
  consequence 
  of 
  which 
  they 
  were 
  omitted 
  from 
  

   the 
  report 
  of 
  the 
  Canadian 
  survey 
  (decade 
  2) 
  after 
  having 
  been 
  

   figured. 
  

  

  Soon 
  still 
  more 
  facts 
  began 
  to 
  accumulate 
  which 
  threw 
  doubt 
  

   on 
  that 
  correlation, 
  and 
  finally, 
  in. 
  1877, 
  Hall 
  read 
  a 
  paper 
  (17) 
  

   before 
  the 
  American 
  association 
  for 
  the 
  advancement 
  of 
  science, 
  

   in 
  which 
  the 
  famous 
  investigator 
  fully 
  relates 
  how 
  in 
  joint 
  ex- 
  

   cursions 
  with 
  his 
  friend, 
  Sir 
  William 
  Logan, 
  along 
  the 
  Hudson 
  

   river 
  and 
  the 
  adjacent 
  counties, 
  the 
  evidence 
  on 
  which 
  the 
  ori- 
  

   ginal 
  conclusions 
  were 
  based, 
  was 
  reviewed. 
  He 
  said: 
  

  

  A 
  farther 
  careful 
  study 
  of 
  the 
  materials 
  collected 
  showed 
  con- 
  

   clusively 
  that, 
  within 
  the 
  limits 
  indicated, 
  all 
  the 
  fossils 
  were 
  of 
  

   the 
  second 
  fauna. 
  Many 
  of 
  the 
  species 
  of 
  graptolites, 
  so' 
  abun- 
  

   dant 
  in 
  certain 
  localities 
  of 
  the 
  disturbed 
  and 
  partly 
  altered 
  

   shales, 
  were 
  also 
  found 
  in 
  the 
  shales 
  and 
  sandstones 
  which 
  gradu- 
  

   ally 
  assumed 
  an 
  undisturbed 
  and 
  unaltered 
  condition 
  within 
  a 
  few 
  

   miles 
  west 
  of 
  the 
  river, 
  extending 
  thence 
  through 
  the 
  Mohawk 
  

   valley, 
  where 
  they 
  rest 
  conformably 
  upon 
  the 
  limestones 
  of 
  the 
  

   Trenton 
  group. 
  

  

  With 
  this 
  declaration 
  Hall 
  returned 
  to 
  his 
  former 
  view 
  of 
  the 
  

   continuity 
  of 
  the 
  graptolite-bearing 
  beds 
  of 
  the 
  Hudson 
  river 
  

   shales 
  with 
  the 
  Frankfort 
  slates 
  of 
  the 
  Mohawk 
  valley 
  and 
  the 
  

   Lorraine 
  beds 
  of 
  the 
  northwestern 
  region. 
  It 
  is 
  a 
  misfortune 
  

   that 
  he 
  does 
  not 
  specify 
  the 
  many 
  species 
  of 
  graptolites 
  which 
  he 
  

   says 
  are 
  common 
  to 
  the 
  altered 
  shales 
  of 
  the 
  Hudson 
  valley 
  and 
  

   to 
  the 
  more 
  western 
  undisturbed 
  beds, 
  as 
  this 
  observation 
  forms 
  

   the 
  principal 
  base 
  of 
  his 
  correlation 
  and 
  has 
  not 
  been 
  verified 
  

   by 
  other 
  observers, 
  while 
  it 
  disagrees 
  with 
  the 
  writer's 
  results 
  

   on 
  the 
  distribution 
  of 
  the 
  Normans 
  kill 
  fauna 
  to 
  the 
  west 
  of 
  the 
  

   Hudson 
  valley. 
  

  

  The 
  cause 
  of 
  the 
  misinterpretation 
  of 
  the 
  rocks 
  of 
  the 
  Hudson 
  

   valley 
  is, 
  in 
  the 
  same 
  address 
  (17:261), 
  very 
  appropriately 
  at- 
  

   tributed 
  to 
  the 
  "fact, 
  that 
  not 
  only 
  the 
  rocks 
  in 
  the 
  immediate 
  

   valley 
  of 
  the 
  Hudson, 
  but 
  also 
  those 
  between 
  the 
  river 
  and 
  ili«- 
  

   eastern 
  limit 
  of 
  the 
  state, 
  were 
  treated 
  as 
  a 
  single 
  group 
  or 
  s\ 
  s 
  

  

  