﻿336 
  Forty-seventh 
  Report 
  on 
  the 
  State 
  Museum. 
  

  

  495 
  

  

  At 
  this 
  level 
  the 
  shales 
  become 
  less 
  blue, 
  more 
  slaty 
  and 
  

   with 
  cleaner 
  cleavage, 
  and 
  the 
  fauna 
  rapidly 
  changes. 
  Toward 
  

   the 
  bottom 
  of 
  this 
  mass 
  the 
  shales 
  become 
  very 
  black 
  and 
  

   bituminous. 
  Fossils 
  much 
  less 
  abundant 
  than 
  above 
  and 
  not 
  

   uniformly 
  distributed, 
  but 
  in 
  thin 
  beds 
  at 
  distinct 
  horizons. 
  

   Thus 
  Liorhynchus 
  multicosta 
  is 
  very 
  abundant 
  at 
  495, 
  where 
  a 
  

   thin 
  layer 
  is 
  composed 
  of 
  it; 
  Modiomorpha 
  subalata 
  at 
  505; 
  

   Gonialites 
  uniayigularis 
  and 
  Z/unulicardium 
  fragile 
  abound 
  

   at 
  510, 
  and 
  Styliolina 
  fissurella, 
  with 
  undetermined 
  plant 
  

   remains, 
  at 
  512. 
  The 
  other 
  commoner 
  species 
  are 
  Chonetes 
  

   scitula, 
  Ambocoelia 
  prceumbona 
  and 
  an 
  undetermined 
  form 
  of 
  

   Panenka. 
  Those 
  of 
  less 
  frequent 
  occurrence 
  are 
  Ambocoelia 
  

   umbonata, 
  Productella 
  spinulicosta, 
  Spirifer 
  mucronatus, 
  

   Pleurotomaria 
  rugulata, 
  and 
  an 
  undescribed, 
  perhaps 
  new, 
  

   form 
  of 
  Goniatites. 
  

  

  