﻿m 
  \v 
  ITOBB 
  i: 
  mi 
  si 
  

  

  ad 
  belonging 
  to 
  one 
  geologic 
  age, 
  thus 
  creating 
  

   afusion 
  in 
  whatever 
  asped 
  they 
  were 
  regarded". 
  The 
  occur- 
  

   lithologically 
  homogeneous, 
  bnl 
  faunistically 
  hetero- 
  

   dng 
  apparently 
  a 
  stratigraphie 
  unit, 
  has 
  

   o 
  the 
  cause 
  of 
  endless 
  discussion 
  and 
  confusion, 
  as 
  the 
  Ta- 
  

   Q 
  bis, 
  the 
  Hudson 
  river 
  group 
  controversy 
  fully 
  

  

  demonstrate, 
  li 
  appears, 
  now, 
  that, 
  while 
  Hall 
  freed 
  the 
  Hudson 
  

   groHp, 
  by 
  insisting 
  on 
  its 
  upper 
  Champlainic 
  (Siluric) 
  age, 
  

   from 
  b 
  arther 
  involved 
  in 
  the 
  Taconic 
  controversy, 
  he, 
  to 
  a 
  

  

  <••' 
  ommitted 
  a 
  similar 
  error 
  by 
  uniting 
  the 
  Lorraine 
  

  

  Normans 
  kill 
  faunas 
  in 
  one 
  group, 
  for 
  ibis 
  correlation 
  is. 
  as 
  

   shown 
  still 
  farther 
  on, 
  the 
  principal 
  cause 
  of 
  the 
  con- 
  

   troversy 
  in 
  regard 
  to 
  the 
  age 
  of 
  the 
  Hudson 
  river 
  group. 
  

  

  R. 
  P. 
  Whitfield 
  

  

  The 
  composite 
  character 
  of 
  the 
  Hudson 
  river 
  beds 
  was 
  first 
  posi- 
  

   'I 
  by 
  B. 
  P. 
  Whitfield 
  in 
  a 
  letter 
  written 
  in 
  1875 
  to 
  Dr 
  

   \. 
  White 
  (16). 
  Prof. 
  Whitfield's 
  most 
  important 
  statements 
  

   in 
  regard 
  to 
  our 
  investigation 
  are: 
  

  

  Prom 
  the 
  evidence 
  furnished 
  by 
  these 
  fossils 
  (graptolites), 
  I 
  

   have 
  reached 
  the 
  conclusion 
  thai 
  the 
  graptolite-bearing 
  laj 
  

   there 
  are 
  of 
  the 
  age 
  of 
  the 
  I 
  tica 
  slate, 
  the 
  following 
  being 
  .1 
  sum- 
  

   mary 
  of 
  the 
  facts 
  1 
  have 
  observed. 
  

  

  I 
  have 
  found 
  the 
  following 
  Bpecies 
  common 
  to 
  both 
  the 
  grapto- 
  

   lite 
  layers 
  a1 
  Normans 
  kill 
  and 
  those 
  of 
  the 
  Utica 
  slate 
  formation 
  

   he 
  mouth 
  of 
  Oztungo 
  creek 
  near 
  Fort 
  Plain 
  N. 
  Y.: 
  <; 
  ra 
  pto- 
  

   iithus 
  . 
  M 
  11 
  g 
  ra 
  p 
  tus) 
  s 
  e 
  r 
  ratulus, 
  Hall. 
  G. 
  (Di'p- 
  

   - 
  aptus) 
  pristis, 
  Hall 
  (not 
  Hisinger), 
  G. 
  (Cli 
  ma- 
  

   1 
  I" 
  " 
  b 
  1 
  bico 
  in 
  i 
  s. 
  Hall 
  and 
  G. 
  (Die 
  ran 
  og 
  pa 
  p 
  

   tus) 
  ra 
  m 
  osus, 
  Hall. 
  

   •' 
  b1 
  south 
  of 
  Troy, 
  in 
  the 
  shaly 
  partings 
  between 
  layers 
  of 
  

   amorphic 
  limestone, 
  I 
  have 
  found 
  a 
  Bpecies 
  of 
  graptolite 
  in 
  

   ibundance 
  Indistinguishable 
  from 
  G. 
  amplexi 
  c 
  a 
  u 
  lis 
  

   the 
  Trenton 
  limestone 
  of 
  Herkimer 
  county, 
  X. 
  Y. 
  

   me 
  species 
  was 
  also 
  found 
  abundantly 
  in 
  the 
  yard 
  of 
  the 
  

   nal 
  at 
  Watervliel 
  bj 
  Capt 
  i 
  i 
  Dutton, 
  U. 
  B. 
  a. 
  

  

  the 
  foregoing 
  I 
  infer 
  thai 
  the 
  slates 
  belo* 
  Troy 
  and 
  

  

  -• 
  " 
  ;i1 
  yard, 
  together 
  with 
  the 
  associated 
  metamorphic 
  

   lim< 
  equivalents 
  of 
  the 
  Trenton 
  limestone. 
  

  

  