﻿\i.\v 
  J 
  

  

  which 
  bas 
  been 
  taken 
  up 
  by 
  the 
  textbooks 
  and 
  has 
  pome 
  into 
  

  

  In 
  iln- 
  same 
  volume 
  Hall 
  described 
  Borne 
  new 
  graptolites 
  from 
  

   the 
  Point 
  Llvia 
  shales 
  oi 
  Canada 
  as 
  coming 
  from 
  near 
  the 
  sum- 
  

   be 
  Hudson 
  rr 
  >up 
  i|». 
  503), 
  a 
  correlation 
  to 
  which 
  

   on 
  was 
  taken 
  l>.\ 
  Billings 
  (9), 
  who 
  not 
  only 
  claimed 
  a 
  

   for 
  the 
  Point 
  l 
  ad 
  Quebec, 
  bu1 
  also 
  for 
  the 
  

   ins 
  kill 
  graptoHtes. 
  Billings 
  derives 
  his 
  conclusion 
  from 
  

   d 
  with 
  the 
  \«iii«al 
  range 
  of 
  the 
  graptolites 
  in 
  E 
  

   land, 
  a 
  proceeding 
  which, 
  25 
  years 
  later, 
  was 
  repeated 
  by 
  Lap 
  

   ill 
  and. 
  interestingly 
  enough, 
  with 
  similar 
  results. 
  This 
  

   paper 
  of 
  Billings's 
  is 
  indicative 
  of 
  the 
  complete 
  change 
  in 
  the 
  

   correlation 
  of 
  the 
  Hudson 
  river 
  shales 
  which, 
  about 
  this 
  time, 
  

   was 
  wrought 
  by 
  the 
  influence 
  of 
  the 
  Canadian 
  survey. 
  The 
  lad 
  

   influenced 
  by 
  the 
  presence 
  of 
  primordial 
  fossils 
  in 
  the 
  Hudson 
  

   val. 
  _ 
  mi. 
  assumed 
  that 
  the 
  older 
  rocks 
  of 
  Canada 
  and 
  of 
  the 
  

   Champlain 
  valley 
  extended 
  into 
  the 
  Hudson 
  valley. 
  The 
  influ- 
  

   ence 
  of 
  Emmons, 
  who 
  had 
  extended 
  the 
  term, 
  Taconic, 
  to 
  the 
  

   shales 
  of 
  the 
  Hudson 
  valley 
  and 
  asserted 
  the 
  continuation 
  of 
  the 
  

   Hudson 
  river 
  shales 
  to 
  the 
  primordial 
  region 
  of 
  Quebec, 
  was 
  also 
  

   powerful 
  in 
  shaping 
  Hall's 
  view 
  of 
  the 
  older 
  Lower 
  Siluric 
  i 
  

   of 
  the 
  Hudson 
  river 
  shah-. 
  When 
  Hall 
  received 
  the 
  graptolites 
  

   of 
  the 
  < 
  Canadian 
  survey 
  for 
  description, 
  and 
  believed 
  thai 
  hi 
  n 
  i 
  

   nized 
  in 
  species 
  from 
  Point 
  Levis 
  and 
  other 
  localities 
  on 
  the 
  

   s 
  ' 
  Lawrence 
  belo^i 
  Quebec, 
  Normans 
  kill 
  species, 
  he 
  came 
  out 
  

   •I- 
  alj 
  .l<», 
  for 
  the 
  "primordial 
  (Quebec) 
  age" 
  of 
  the 
  bulk 
  of 
  

   th«- 
  Hudson 
  river 
  beds, 
  assuming 
  with 
  Logan, 
  jhat 
  the 
  two 
  or 
  

   Hn- 
  irrenees 
  of 
  a 
  few 
  f«>vxj]s 
  of 
  the 
  "second 
  fauna" 
  were 
  

   "outliers 
  of 
  insignificant 
  extent 
  embraced 
  within 
  tie- 
  folds 
  of 
  

   the 
  older 
  rocks 
  or 
  resting 
  upon 
  these 
  primordial 
  beds 
  which 
  

   formed 
  the 
  fundamental 
  rocks 
  oi 
  the 
  valley, 
  and 
  that 
  the 
  de- 
  

   -• 
  d 
  and 
  altered 
  Hudson 
  river 
  beds 
  were 
  separated 
  from 
  t 
  lie 
  

   unaltered 
  beds 
  in 
  the 
  west 
  by 
  a 
  fault 
  *\ 
  He, 
  therefore, 
  dropped 
  

   term 
  Hudson 
  river 
  group, 
  stating 
  expressly 
  (10:444) 
  that 
  

   - 
  iptolites 
  of 
  the 
  Hudson 
  rallej 
  do 
  not 
  belong 
  to 
  the 
  second 
  

   fauna, 
  but 
  "hold 
  a 
  low< 
  sition 
  and 
  belong 
  to 
  the 
  great 
  mi 
  

   of 
  rh( 
  - 
  below". 
  

  

  