﻿284 
  EEPORT 
  UNITED 
  STATES 
  GEOLOGICAL 
  SURVEY. 
  

  

  tions 
  of 
  the 
  transformation 
  ; 
  a 
  portion 
  had 
  the 
  appearance 
  of 
  soft 
  de- 
  

   cayed 
  wood, 
  which 
  crumbled 
  in 
  handling, 
  and 
  other 
  parts 
  ringing 
  like 
  

   flint 
  under 
  the 
  hammer. 
  Occasionally 
  specimens 
  were 
  converted 
  into 
  

   chalcedony, 
  but 
  the 
  annual 
  growth 
  of 
  the 
  wood 
  distinctly 
  remained. 
  In 
  

   a 
  single 
  instance 
  we 
  detected 
  the 
  fibrous 
  structure 
  of 
  the 
  palm. 
  

  

  Tt 
  is 
  rather 
  singular 
  that 
  we 
  have 
  never 
  found 
  the 
  leaves 
  so 
  common 
  

   in 
  our 
  Dakota, 
  and 
  which 
  are 
  equally 
  numerous 
  in 
  the 
  Tertiary 
  of 
  Col- 
  

   orado. 
  

  

  A 
  new 
  and 
  rare 
  form 
  of 
  crinoid, 
  first 
  found 
  by 
  Professor 
  Marsh 
  in 
  the 
  

   Uinta 
  Mountains, 
  was, 
  in 
  a 
  few 
  instances, 
  procured 
  by 
  our 
  party. 
  It 
  is 
  

   the 
  only 
  crinoid 
  known 
  in 
  the 
  American 
  Cretaceous. 
  It 
  is 
  described 
  by 
  

   G. 
  B. 
  Grinnell 
  in 
  the 
  American 
  Journal 
  of 
  Science 
  and 
  Art, 
  July, 
  1876, 
  

   page 
  81, 
  as 
  Uintacrinus 
  socialis. 
  

  

  Of 
  mollusks, 
  the 
  most 
  common 
  are 
  Ostrea 
  congesta 
  and 
  Inoeeramus 
  

   problemaUcus. 
  Less 
  common, 
  but 
  still 
  seen 
  in 
  many 
  strata, 
  are 
  frag- 
  

   ments 
  of 
  the 
  large 
  Haploscapha, 
  with 
  occasionally 
  a 
  perfect 
  specimen. 
  

   Another 
  large 
  bivalve 
  we 
  have 
  never 
  seen 
  described 
  measures 
  from 
  30 
  

   to 
  33 
  inches 
  in 
  length. 
  It 
  is 
  thin, 
  with 
  a 
  transverse 
  fiber 
  like 
  the 
  Ino- 
  

   cerami^ 
  and 
  always 
  lies 
  crushed 
  flat 
  in 
  numerous 
  fragments, 
  but 
  lying 
  

   in 
  their 
  normal 
  position. 
  A 
  few 
  Gryphea; 
  also 
  fragments, 
  frequently 
  

   weighing 
  ten 
  pounds, 
  of 
  a 
  large 
  Hippurites 
  near 
  H. 
  Toncasianus. 
  ]^ear 
  

   Sheridan, 
  we 
  recently 
  discovered 
  a 
  bed 
  of 
  Baculites, 
  and 
  on 
  referring 
  

   them 
  to 
  Prof. 
  F. 
  B. 
  Meek 
  for 
  identification, 
  he 
  decides 
  they 
  are 
  B. 
  anceps, 
  

   not 
  before 
  found 
  nearer 
  than 
  New 
  Mexico. 
  In 
  his 
  kiiid 
  response 
  to 
  

   my 
  inquiries, 
  dated 
  November 
  21, 
  1876, 
  he 
  writes 
  : 
  " 
  One 
  fact 
  in 
  regard 
  

   to 
  your 
  specimens, 
  however, 
  is 
  curious 
  to 
  me. 
  All 
  the 
  other 
  forms 
  like 
  

   this 
  I 
  have 
  ever 
  seen 
  from 
  any 
  part 
  of 
  the 
  far 
  West 
  come 
  from 
  our 
  Nos. 
  

   4 
  and 
  5 
  *; 
  while 
  all 
  of 
  the 
  other 
  species 
  of 
  anything 
  yet 
  known 
  from 
  

   those 
  upper 
  rocks 
  is 
  distinct 
  from 
  anything 
  found 
  in'Nos. 
  2 
  or 
  3.t 
  

   Can 
  it 
  be 
  possible 
  that 
  you 
  might 
  have 
  found 
  this 
  in 
  an 
  outlier 
  of 
  Nos. 
  

   4 
  or 
  5 
  ? 
  It 
  has 
  the 
  shell-substance 
  well 
  preserved, 
  like 
  the 
  fossils 
  of 
  

   those 
  upper 
  beds, 
  while 
  those 
  in 
  the 
  lower 
  beds 
  are 
  usually 
  casts." 
  * 
  * 
  

  

  The 
  situation 
  of 
  the 
  Baculites 
  were, 
  however, 
  clearly 
  in 
  the 
  Niobrara, 
  

   as 
  the 
  characteristic 
  fish 
  and 
  Saurians 
  were 
  found 
  15 
  or 
  25 
  feet 
  above, 
  in 
  

   the 
  bluffs 
  not 
  200 
  yards 
  distant. 
  It 
  is 
  also 
  a 
  common 
  incident 
  to 
  find 
  

   the 
  shell-substance 
  of 
  Inoeeramus 
  problemaUcus, 
  &c., 
  in 
  excellent 
  pres- 
  

   ervation 
  in 
  Wallace 
  County. 
  Almost 
  all 
  the 
  shells 
  and 
  fragments 
  are 
  

   covered 
  in 
  part 
  by 
  the 
  Ostrea 
  congesta, 
  which 
  abound 
  everywhere. 
  

  

  But 
  the 
  great 
  feature 
  of 
  this 
  division 
  of 
  the 
  Cretaceous 
  consists 
  in 
  its 
  

   varied 
  and 
  rare 
  forms 
  of 
  the 
  vertebrate 
  fossils. 
  Three 
  seasons 
  of 
  six 
  or 
  

   seven 
  months 
  each 
  (1874, 
  '75, 
  '76) 
  have 
  been 
  spent 
  by 
  myself, 
  with 
  two 
  

   to 
  five 
  assistants, 
  in 
  collecting 
  these 
  vertebrates 
  for 
  Yale 
  College. 
  

  

  The 
  least 
  interesting 
  are 
  the 
  fish, 
  which 
  have, 
  however, 
  given 
  us 
  many 
  

   new 
  species 
  and 
  some 
  new 
  genera. 
  The 
  small 
  ones 
  are 
  nearly 
  entire, 
  

   but 
  the 
  larger 
  are 
  represented 
  only 
  by 
  well-preserved 
  portions 
  of 
  the 
  

   skeletons. 
  Teeth 
  of 
  Salachians 
  are 
  quite 
  common. 
  At 
  one 
  locality 
  

   over 
  400 
  were 
  collected 
  in 
  an 
  area 
  of 
  30 
  inches, 
  and 
  apparently 
  from 
  the 
  

   jaws 
  of 
  one 
  individual 
  — 
  Ptycodus 
  mortoni 
  — 
  and 
  all 
  in 
  excellent 
  preserva- 
  

   tion. 
  

  

  Quite 
  recently 
  I 
  had 
  the 
  good 
  fortune 
  to 
  find 
  the 
  teeth, 
  cartilaginous 
  

   jaw, 
  and 
  vertebrae 
  of 
  a 
  shark 
  — 
  Oaleocerdo 
  falcatus^thvee 
  portions, 
  which, 
  

   I 
  think, 
  have 
  never 
  hitherto 
  been 
  found 
  together. 
  The 
  flat, 
  porous 
  ver- 
  

   tebrae 
  had 
  occasionally 
  been 
  collected, 
  but 
  we 
  had 
  been 
  unable 
  to 
  give 
  

   them 
  their 
  generic 
  name. 
  The 
  teeth 
  were 
  frequently 
  procured. 
  

  

  • 
  Fort 
  Pierre 
  and 
  Fox 
  Hill 
  groups. 
  t 
  Fort 
  Beutou 
  and 
  Niobrara. 
  

  

  