﻿FOURTH 
  REPORT 
  07 
  THE 
  DIRECTOR 
  I907 
  53 
  

  

  Attention 
  has 
  been 
  called 
  by 
  Professor 
  Schuchert 
  to 
  the 
  similarity 
  

   between 
  the 
  Middle 
  Devonic 
  fauna 
  of 
  the 
  Hudson 
  Bay 
  region, 
  

   and 
  that 
  of 
  the 
  Mississippian 
  Onondaga. 
  A 
  number 
  of 
  considera- 
  

   tions 
  are 
  proffered 
  to 
  show 
  that 
  while 
  each 
  of 
  these 
  faunas 
  has 
  its 
  

   individual 
  fades, 
  yet 
  both 
  are 
  of 
  that 
  type 
  which 
  characterizes 
  the 
  

   American, 
  in 
  contradistinction 
  to 
  the 
  Eurasian 
  province 
  ; 
  and 
  more- 
  

   over, 
  they 
  differ 
  both 
  in 
  horizon 
  and 
  facies 
  from 
  the 
  Stringocephalus 
  

   zone 
  of 
  western 
  and 
  northwestern 
  Canada. 
  It 
  is 
  inferred, 
  accord- 
  

   ingly, 
  that 
  the 
  Hudson 
  Bay 
  Devonic 
  area 
  was 
  entirely 
  shut 
  off 
  from 
  

   communication 
  with 
  the 
  Dakota 
  sea, 
  but 
  on 
  the 
  other 
  hand 
  it 
  is 
  

   thought 
  probable 
  that 
  intermittent 
  connection 
  existed 
  between 
  the 
  

   former 
  basin 
  and 
  the 
  Mississippian 
  sea. 
  An 
  opening 
  is 
  also 
  posited 
  

   by 
  the 
  same 
  writer, 
  lasting 
  throughout 
  the 
  Devonic, 
  between 
  the 
  

   Appalachian 
  and 
  Eurasian 
  provinces, 
  the 
  route 
  leading 
  through 
  the 
  

   so 
  called 
  Connecticut 
  straits, 
  thence 
  along 
  the 
  Gulf 
  of 
  St 
  Lawrence 
  

   and 
  across 
  the 
  Atlantic. 
  Having 
  established 
  what 
  seems 
  to 
  him 
  

   a 
  reasonable 
  basis 
  for 
  the 
  propositions 
  just 
  stated, 
  Professor 
  

   Schuchert 
  sums 
  up 
  his 
  conclusions 
  in 
  regard 
  to 
  Middle 
  Devonic 
  

   faunal 
  distribution 
  in 
  the 
  following 
  paragraph: 
  

  

  " 
  The 
  Onondaga 
  fauna 
  is 
  the 
  outgrowth 
  of 
  the 
  Oriskanian 
  fauna 
  

   of 
  the 
  North 
  Atlantic 
  type 
  plus 
  the 
  migration 
  during 
  Onondaga 
  

   time 
  of 
  other 
  North 
  Atlantic 
  forms 
  by 
  way 
  of 
  the 
  Connecticut 
  

   trough 
  and 
  invasions 
  from 
  the 
  far 
  south 
  through 
  the 
  Indiana 
  basin. 
  

   The 
  Hamilton 
  fauna 
  is 
  the 
  descendant 
  of 
  that 
  of 
  the 
  Onondaga 
  plus 
  

   North 
  European 
  migrants 
  by 
  way 
  of 
  the 
  Connecticut 
  trough, 
  South 
  

   American 
  arrivals 
  by 
  way 
  of 
  the 
  Indiana 
  basin, 
  and 
  slight 
  invasions 
  

   from 
  the 
  Dakota 
  sea 
  by 
  way 
  of 
  Traverse 
  straits. 
  These 
  three 
  

   openings 
  then 
  remained 
  in 
  existence 
  during 
  the 
  greater 
  part 
  of 
  

   Upper 
  Devonic 
  time." 
  

  

  This 
  rather 
  full 
  statement 
  in 
  regard 
  to 
  conceptual 
  waterways 
  has 
  

   been 
  made 
  not 
  for 
  the 
  purpose 
  of 
  criticism, 
  but 
  in 
  order 
  to 
  synthesize 
  

   as 
  far 
  as 
  possible 
  certain 
  elements 
  of 
  apparently 
  conflicting 
  nature. 
  

   The 
  test 
  of 
  a 
  sound 
  judgment 
  is 
  its 
  ability 
  to 
  unify 
  various 
  and 
  

   sometimes 
  even 
  dissonant 
  concepts. 
  In 
  the 
  present 
  instance 
  it 
  

   becomes 
  necessary 
  to 
  reconcile 
  with 
  the 
  evidence 
  furnished 
  by 
  

   Helderbergian 
  and 
  Oriskanian 
  invertebrates 
  in 
  favor 
  of 
  an 
  invasion 
  

   from 
  the 
  northeast, 
  certain 
  other 
  evidence 
  that 
  appears 
  at 
  first 
  sight 
  

   discordant, 
  namely, 
  the 
  failure 
  of 
  anv 
  Lower 
  Devonic 
  vertebrates 
  

   to 
  take 
  part 
  in 
  the 
  migration. 
  As 
  will 
  be 
  seen 
  from 
  an 
  inspection 
  

   of 
  the 
  faunal 
  lists, 
  the 
  abundant 
  and 
  rather 
  diversified 
  fish 
  

   fauna 
  occurring 
  in 
  the 
  synclinal 
  basin 
  of 
  the 
  Restigouche 
  

   near 
  Campbellton, 
  N. 
  B., 
  is 
  without 
  a 
  single 
  representative 
  

   in 
  rocks 
  of 
  Lower 
  or 
  Middle 
  Devonic 
  age 
  in 
  the 
  Appalachian 
  

   province. 
  No 
  traits 
  are 
  observed 
  in 
  the 
  Onondaga 
  or 
  Hamilton 
  fish 
  

   faunas 
  which 
  can 
  be 
  ascribed 
  to 
  an 
  immigration 
  from 
  eastern 
  

   Canada 
  by 
  way 
  of 
  the 
  putative 
  water 
  route 
  called 
  by 
  Clarke 
  the 
  

   'Appalachian 
  strait," 
  and 
  by 
  Dana 
  the 
  " 
  Connecticut 
  trough," 
  which 
  

   is 
  supposed 
  to 
  have 
  been 
  open 
  during 
  the 
  late 
  Siluric 
  and 
  greater 
  

   part 
  of 
  the 
  Devonic. 
  None 
  of 
  the 
  Appalachian 
  Mesodevonic 
  verte- 
  

   brates 
  can 
  be 
  regarded 
  as 
  the 
  genetic 
  descendant 
  of 
  forms 
  that 
  

  

  