﻿Spencer 
  — 
  Devonian 
  Strata 
  in 
  Colorado. 
  131 
  

  

  were 
  found 
  which 
  had 
  a 
  Devonian 
  aspect, 
  but, 
  in 
  the 
  absence 
  

   of 
  any 
  stratigraphic 
  criterion, 
  the 
  data 
  were 
  not 
  considered 
  to 
  

   be 
  sufficient 
  to 
  warrant 
  the 
  mapping 
  or 
  the 
  description 
  of 
  the 
  

   Devonian 
  in 
  the 
  Anthracite-Crested 
  Butte 
  Folio, 
  published 
  in 
  

   1S9L 
  Part 
  of 
  the 
  fossils 
  which 
  were 
  collected 
  in 
  this 
  region 
  

   are 
  in 
  the 
  National 
  Museum 
  and 
  have 
  been 
  examined 
  by 
  Dr. 
  

   Girty, 
  who 
  finds 
  among 
  them 
  forms 
  identical 
  with 
  those 
  from 
  

   the 
  Devonian 
  limestone 
  from 
  the 
  San 
  Juan 
  region. 
  The 
  

   Devonian 
  fauna 
  is 
  succeeded 
  by 
  a 
  characteristic 
  assemblage 
  of 
  

   Lower 
  Carboniferous 
  forms. 
  

  

  In 
  the 
  summer 
  of 
  1889, 
  at 
  the 
  instance 
  of 
  Mr. 
  Emmons, 
  a 
  

   careful 
  search 
  for 
  fossils 
  was 
  made 
  by 
  T. 
  W. 
  Stanton, 
  in 
  the 
  

   lower 
  Paleozoic 
  strata 
  near 
  Glenwood 
  Springs. 
  Rhynconella 
  

   Endlichi 
  was 
  one 
  of 
  the 
  few 
  forms 
  collected, 
  the 
  rest 
  being 
  

   either 
  Lower 
  Carboniferous 
  or 
  pre-Devonian. 
  At 
  the 
  time, 
  

   this 
  was 
  taken 
  as 
  negative 
  evidenee 
  in 
  favor 
  of 
  the 
  absence 
  of 
  

   Devonian, 
  but 
  since 
  Rhynconella 
  Endlichi 
  is 
  now 
  known 
  to 
  be 
  

   of 
  that 
  age, 
  it 
  seems 
  probable 
  that 
  the 
  Devonian 
  limestones 
  

   are 
  present 
  at 
  this 
  place. 
  The 
  " 
  Parting 
  Quartzite 
  " 
  is 
  also 
  

   probably 
  present, 
  though 
  its 
  true 
  relations 
  are 
  obscured 
  by 
  the 
  

   faulting 
  which 
  has 
  taken 
  place.* 
  

  

  At 
  Aspen, 
  Spurrf 
  has 
  described 
  the 
  same 
  stratigraphic 
  ele- 
  

   ments 
  as 
  those 
  recognized 
  at 
  Leadville 
  : 
  the 
  white 
  limestone, 
  

   the 
  u 
  Parting 
  Quartzite," 
  and 
  the 
  blue 
  limestone 
  are 
  all 
  present. 
  

   Fish 
  remains 
  of 
  a 
  Devonian 
  type, 
  which 
  were 
  found 
  in 
  the 
  

   " 
  Parting 
  Quartzite," 
  furnish 
  the 
  basis 
  for 
  correlating 
  this 
  

   series 
  with 
  the 
  Devonian 
  of 
  the 
  Kanab 
  valley 
  in 
  Southern 
  

   Utah 
  and 
  Northern 
  Arizona, 
  as 
  described 
  by 
  Walcott.J 
  The 
  

   stratigraphic 
  position 
  and 
  lithology 
  of 
  the 
  siliceous 
  series 
  in 
  

   both 
  regions 
  are 
  similar 
  and 
  have 
  been 
  considered 
  by 
  Spurr 
  a 
  

   sufficient 
  basis 
  of 
  correlation. 
  

  

  The 
  fossils 
  occurring 
  at 
  Salida 
  have 
  been 
  determined 
  as 
  

   follows 
  : 
  

  

  Monotrypella 
  sps. 
  a, 
  b, 
  and 
  c. 
  Spirifer 
  disjunct 
  us 
  var. 
  Ani- 
  

   Schizophoria 
  striatula. 
  masensis. 
  

  

  OrtJwthetes 
  Chemung 
  ensis. 
  Athyris 
  Color 
  adcensis. 
  

  

  Orthothetes 
  Chemungensis 
  var. 
  Camarotcechia 
  [Rhynconella) 
  

   Productella 
  subalata? 
  Endlichi. 
  

  

  Productella 
  subalata 
  var. 
  Camarotcechia 
  contractu 
  f 
  

  

  Productella 
  semiglobosa. 
  Euomphalus 
  clymenioides. 
  

  

  Orthoceras 
  sp. 
  a. 
  

  

  * 
  Opinion 
  of 
  Mr. 
  Emmons 
  in 
  conversation. 
  

  

  f 
  Monographs 
  of 
  U. 
  S. 
  Geol. 
  Survey, 
  xxxi, 
  pp. 
  9-30. 
  

  

  \ 
  This 
  Journal, 
  xx, 
  p. 
  224. 
  

  

  