﻿284 
  W. 
  H. 
  Tivenhofel 
  — 
  The 
  Comancliean 
  and 
  

  

  Cycadeoidea 
  munita 
  and 
  identified 
  foliage 
  as 
  belonging 
  

   to 
  Glyptostrobus 
  graeillimus 
  Lx. 
  10 
  

  

  The 
  Cheyenne 
  sandstones 
  are 
  of 
  terrestrial 
  origin 
  and 
  

   were 
  deposited 
  on 
  relatively 
  flat 
  lands 
  near 
  the 
  sea. 
  

   They 
  contain 
  gypsum 
  crystals 
  which, 
  were 
  they 
  contem- 
  

   poraneous 
  in 
  deposition 
  with 
  the 
  sands, 
  would 
  indicate 
  

   that 
  marine 
  waters 
  were 
  concerned 
  in 
  their 
  deposition 
  

   and 
  that 
  the 
  climatic 
  conditions 
  were 
  those 
  of 
  aridity. 
  

   The 
  writer 
  is 
  of 
  the 
  opinion 
  that 
  such 
  were 
  the 
  climatic 
  

   conditions, 
  but 
  that 
  the 
  gypsum 
  was 
  brought 
  in 
  either 
  by 
  

   sea 
  water 
  at 
  the 
  time 
  of 
  the 
  Kiowa 
  submergence 
  or 
  from 
  

   the 
  Kiowa 
  by 
  ground 
  water 
  after 
  the 
  uplift 
  of 
  the 
  latter. 
  

  

  The 
  Kiowa 
  shales 
  and 
  limestones 
  are 
  near-shore 
  

   deposits, 
  consisting 
  of 
  alternations 
  of 
  shell 
  limestones 
  

   filled 
  with 
  pelecypods 
  and 
  gastropods, 
  and 
  calcareous 
  

   and 
  bituminous 
  clay 
  shales. 
  The 
  bituminous 
  shales 
  con- 
  

   tain 
  few 
  fossils 
  and 
  those 
  present 
  are 
  not 
  of 
  large 
  size. 
  

   Shales 
  of 
  this 
  character 
  are 
  most 
  common 
  in 
  the 
  lower 
  

   half 
  of 
  the 
  formation 
  and 
  are 
  probably 
  not 
  typically 
  

   marine, 
  but 
  deposits 
  of 
  enclosed 
  bays 
  similar 
  to 
  those 
  in 
  

   which 
  the 
  black 
  muds 
  of 
  the 
  east 
  Baltic 
  are 
  now 
  deposit- 
  

   ing. 
  11 
  One 
  of 
  the 
  limestones 
  contains 
  small 
  quartz 
  and 
  

   chert 
  pebbles 
  and 
  on 
  several 
  levels 
  in 
  the 
  formation 
  there 
  

   are 
  thin 
  beds 
  of 
  gray 
  sandstone. 
  Gypsum 
  crystals 
  and 
  

   amorphous 
  gypsum 
  are 
  more 
  or 
  less 
  abundant 
  through- 
  

   out 
  and 
  places 
  have 
  been 
  found 
  where 
  the 
  shells 
  lie 
  in 
  a 
  

   matrix 
  which 
  is 
  partially 
  composed 
  of 
  gypsum. 
  This 
  

   points 
  to 
  enclosed 
  seas 
  and 
  arid 
  conditions. 
  At 
  the 
  base 
  

   of 
  the 
  formation 
  there 
  is 
  a 
  6 
  to 
  18 
  inch 
  bed 
  which 
  has 
  

   been 
  called 
  the 
  Champion 
  shell 
  bed; 
  it 
  consists 
  almost 
  

   wholly 
  of 
  small 
  Gryphceas. 
  About 
  fifty 
  species 
  of 
  ma- 
  

   rine 
  invertebrates, 
  thirteen 
  species 
  of 
  vertebrates, 
  and 
  

   a 
  few 
  insect 
  remains 
  have 
  been 
  collected 
  from 
  this 
  for- 
  

   mation. 
  Some 
  of 
  the 
  common 
  invertebrates 
  are: 
  Car- 
  

   dium 
  kansasense 
  Meek, 
  Cyprimeria 
  hiowana 
  Cragin, 
  

   Exogyra 
  texana 
  Eoemer, 
  Gryphcea 
  corrugata 
  Say 
  and 
  

   varieties, 
  G. 
  navia 
  Hall, 
  Osirea 
  quadriplicata 
  Shumard, 
  

   Pecten 
  texanus 
  Eoemer, 
  Protocardia 
  texana 
  Conrad, 
  

   Scliloenbacliia 
  belknappi 
  (Marcou), 
  Scliloenbacliia 
  peru- 
  

   viana 
  (Von 
  Buch) 
  (Marcou), 
  Trigonia 
  emoryi 
  Conrad, 
  

   Turrit 
  ella 
  near 
  T. 
  seriatim-granulata 
  Eoemer. 
  

  

  10 
  F. 
  W. 
  Cragin, 
  Am. 
  Geol., 
  16, 
  263, 
  1895. 
  

  

  n 
  W. 
  H. 
  Twenhofel, 
  this 
  Journal, 
  40, 
  272-280, 
  1915. 
  

  

  