﻿286 
  REPORT 
  UNITED 
  STATES 
  GEOLOGICAL 
  SURVEY. 
  

  

  feet 
  long, 
  while 
  two 
  species 
  were 
  only 
  6 
  feet. 
  Most 
  frequently 
  they 
  were 
  

   from 
  25 
  to 
  40. 
  

  

  The 
  specimens 
  are 
  frequently 
  represented 
  by 
  a 
  few 
  bones 
  washed 
  out 
  

   and 
  lying 
  exposed. 
  Buc 
  the 
  best 
  are 
  obtained 
  by 
  finding 
  a 
  projecting 
  

   fragment, 
  and 
  . 
  then 
  following 
  the 
  skeleton 
  into 
  the 
  compact 
  shale 
  or 
  

   chalk. 
  This 
  sometimes 
  requires 
  much 
  hard 
  labor, 
  but 
  is 
  the 
  most 
  satis- 
  

   factory, 
  as 
  the 
  fossils 
  are, 
  in 
  such 
  cases, 
  in 
  a 
  better 
  state 
  of 
  preserva- 
  

   tion. 
  A 
  single 
  specimen 
  has 
  cost 
  us 
  as 
  much 
  as 
  six 
  days' 
  labor. 
  As 
  the 
  

   bones 
  were 
  sometimes 
  friable, 
  sketches 
  of 
  the 
  best 
  specimens 
  were 
  made 
  

   before 
  removal. 
  The 
  fossilizing 
  material 
  is 
  lime 
  combined 
  with 
  a 
  little 
  

   silica, 
  and 
  the 
  minute 
  stria 
  and 
  muscle 
  markings 
  were 
  in 
  most 
  excellent 
  

   preservation. 
  But 
  in 
  some 
  cases 
  they 
  were 
  impregnated 
  with 
  gypsum 
  

   or 
  iron 
  (sulphide 
  and 
  oxide), 
  when 
  the 
  fine 
  texture 
  and 
  characteristic 
  

   markings 
  were 
  destroyed, 
  and 
  the 
  fossils 
  were 
  almost 
  worthless. 
  

  

  Our 
  researches 
  were 
  confined 
  to 
  the 
  slides 
  and 
  ravines 
  which 
  had 
  ex- 
  

   posed 
  the 
  chalk 
  and 
  shales. 
  These 
  constituted 
  but 
  a 
  small 
  portion 
  of 
  the 
  

   country, 
  but 
  are 
  slowly 
  being 
  enlarged 
  by 
  the 
  action 
  of 
  the 
  elements. 
  

   Miles 
  of 
  these 
  exposures 
  yielded 
  us 
  nothing, 
  and 
  again 
  a 
  small 
  area 
  

   furnished 
  good 
  specime'ns. 
  The 
  animals 
  appeared 
  to 
  have 
  frequented 
  

   favorite 
  haunts 
  to 
  the 
  exclusion 
  of 
  larger 
  areas. 
  Three 
  long 
  seasons 
  

   spent 
  on 
  this 
  territory, 
  besides 
  the 
  labors 
  of 
  other 
  collectors, 
  has 
  nearly 
  

   exhausted 
  the 
  supply 
  of 
  rare 
  fossils. 
  As 
  future 
  washings 
  occur 
  a 
  few 
  

   specimens 
  may 
  be 
  obtained. 
  

  

  Coprolites 
  of 
  fish 
  and 
  Saurians 
  are 
  frequently 
  found, 
  containing 
  the 
  

   remains 
  of 
  the 
  food 
  of 
  the 
  animal. 
  Small 
  fish 
  appeared 
  to 
  be 
  the 
  most 
  

   common 
  food 
  ; 
  but 
  in 
  one 
  instance 
  a 
  rare 
  crustacean 
  was 
  found 
  jire- 
  

   served 
  in 
  this 
  way. 
  The 
  coprolites 
  are 
  not 
  so 
  hard 
  as 
  those 
  of 
  Europe, 
  

   being 
  little 
  firmer 
  than 
  chalk 
  and 
  finer-grained. 
  

  

  The 
  following 
  analysis 
  of 
  a 
  Saurian 
  coprolite 
  from 
  Wallace 
  County 
  is 
  

   by 
  George 
  E. 
  Patrick, 
  professor 
  of 
  chemistry 
  in 
  the 
  University 
  of 
  Kan- 
  

   sas: 
  

  

  Moisture 
  1.22 
  

  

  Organic 
  matter 
  42 
  

  

  Oxide 
  of 
  iron 
  and 
  alumina 
  29. 
  99 
  

  

  Lime 
  24.31 
  

  

  Alkalies, 
  small 
  amount, 
  undetermined. 
  

  

  Silica 
  (combined) 
  19 
  

  

  Phosphoric 
  acid 
  34. 
  88 
  

  

  Carbonic 
  acid 
  7. 
  05 
  

  

  Sulphuric 
  acid 
  1. 
  92 
  

  

  99. 
  98 
  

  

  In 
  some 
  cases, 
  the 
  undigested 
  organic 
  matter 
  (bones) 
  was 
  one-fourth 
  

   of 
  the 
  whole 
  weight. 
  

  

  In 
  some 
  cases 
  we 
  find 
  remains 
  of 
  the 
  indigestible 
  portions 
  of 
  food 
  be- 
  

   tween 
  the 
  ribs, 
  where 
  the 
  stomach 
  was 
  situated. 
  In 
  the 
  Plesiosauri 
  we 
  

   found 
  another 
  interesting 
  feature, 
  showing 
  an 
  aid 
  to 
  digestion 
  similair 
  

   to 
  many 
  living 
  reptiles 
  and 
  some 
  birds. 
  This 
  consisted 
  of 
  well-worn 
  

   siliceous 
  pebbles, 
  from 
  one-fourth 
  to 
  one-half 
  of 
  an 
  inch 
  in 
  diameter. 
  

   They 
  were 
  the 
  more 
  curious, 
  as 
  we 
  never 
  found 
  such 
  pebbles 
  in 
  the 
  

   chalk 
  or 
  shales 
  of 
  the 
  Niobrara. 
  How 
  far 
  the 
  Saurians 
  wandered 
  to 
  

   collect 
  them 
  is 
  a 
  perplexing 
  problem. 
  Their 
  structure 
  does 
  not 
  indicate 
  

   much 
  ability 
  to 
  crawl 
  on 
  land, 
  and 
  yet 
  it 
  is 
  probable 
  that 
  they 
  must 
  

   have 
  frequented 
  some 
  of 
  the 
  islands 
  of 
  the 
  old 
  Cretaceous 
  ocean 
  for 
  that 
  

   and 
  other 
  purposes. 
  As 
  such 
  substances 
  remain 
  in 
  stomachs 
  of 
  low 
  or- 
  

   ganization 
  for 
  a 
  long 
  time, 
  the 
  visits 
  to 
  dry 
  land 
  would 
  not 
  necessarily 
  

   have 
  been 
  very 
  frequent. 
  

  

  