﻿Related 
  Sedimentary 
  Surface 
  Forms. 
  259 
  

  

  and 
  Ontario. 
  48 
  They 
  are 
  common 
  in 
  the 
  Eden 
  and 
  in 
  

   parts 
  of 
  the 
  Richmond 
  Group 
  of 
  the 
  Upper 
  Ordovician 
  

   in 
  the 
  Cincinnati 
  anticline. 
  49 
  They 
  occur 
  at 
  a 
  number 
  of 
  

   localities 
  in 
  the 
  Silurian 
  Brassfield 
  formation 
  of 
  Ken- 
  

   tucky 
  and 
  Ohio. 
  50 
  They 
  were 
  also 
  reported 
  from 
  younger 
  

   Silurian 
  limestones 
  in 
  Ohio 
  51 
  and 
  New 
  York, 
  52 
  from 
  

   Devonian 
  limestones 
  in 
  Ohio 
  53 
  and 
  Ontario, 
  54 
  from 
  the 
  

   Mississippian 
  limestones 
  of 
  Iowa 
  55 
  and 
  from 
  Waverly 
  

   conglomerates 
  of 
  Ohio, 
  56 
  and 
  finally 
  from 
  the 
  Coman- 
  

   chean 
  of 
  Texas. 
  57 
  

  

  Table 
  VI 
  gives 
  a 
  selected 
  number 
  of 
  measurements 
  for 
  

   large 
  fossil 
  current-ripples. 
  

  

  In 
  shape 
  they 
  vary 
  from 
  strongly 
  asymmetrical 
  to 
  com- 
  

   pletely 
  symmetrical 
  ; 
  more 
  than 
  half 
  of 
  all 
  large 
  ripples 
  

   seen 
  in 
  limestones 
  of 
  the 
  Ordovician 
  and 
  Silurian 
  of 
  the 
  

   Cincinnati 
  Anticline 
  were 
  more 
  or 
  less 
  symmetrical. 
  

   Their 
  crests 
  are 
  always 
  broadly 
  rounded 
  like 
  the 
  troughs 
  

   and 
  but 
  rarely 
  show 
  distinct 
  crest 
  lines. 
  

  

  Not 
  one 
  showed 
  any 
  signs 
  of 
  assortment. 
  Shells 
  of 
  

   Rafinesquina, 
  over 
  5 
  cm. 
  long 
  and 
  wide, 
  Bryozoans 
  8 
  to 
  

   10 
  cm. 
  long 
  and 
  over 
  1 
  cm. 
  thick, 
  and, 
  in 
  the 
  Richmond, 
  

   calices 
  of 
  Streptelasma, 
  over 
  10 
  cm. 
  long 
  and 
  over 
  3 
  cm. 
  

   wide, 
  are 
  found 
  scattered 
  equally 
  over 
  crests, 
  sides 
  and 
  

   troughs 
  of 
  the 
  ripples, 
  mixed 
  in 
  almost 
  any 
  proportion 
  

   with 
  finer 
  shell 
  fragments 
  down 
  to 
  the 
  finest 
  matrix 
  filling 
  

   the 
  interstices. 
  

  

  It 
  is 
  very 
  important 
  to 
  note 
  that 
  the 
  same 
  utter 
  lack 
  

   of 
  assortment 
  characterizes 
  the 
  large 
  ripples 
  which 
  are 
  

   found 
  in 
  the 
  Berne 
  member 
  of 
  the 
  Cuyahoga 
  formation 
  of 
  

  

  ^Kuedemann, 
  K., 
  Am. 
  Geol., 
  pp. 
  367 
  ft., 
  1897. 
  Cushing, 
  Bull. 
  N. 
  Y. 
  

   State 
  Mus. 
  Nat. 
  Hist., 
  77, 
  p. 
  34, 
  1905. 
  Miller, 
  ibid., 
  vol. 
  135, 
  p. 
  36, 
  1910. 
  

   Kindle, 
  Jour. 
  Geol., 
  22, 
  pp. 
  703-713, 
  1914. 
  

  

  49 
  See 
  Locke, 
  J. 
  (1838); 
  Orton 
  (1873); 
  Linney, 
  W. 
  M. 
  (1882-1887); 
  

   Knott, 
  W. 
  T. 
  (1885); 
  Perry, 
  N. 
  W. 
  (1889); 
  Shannon, 
  W. 
  P. 
  (1895); 
  

   Foerste, 
  A. 
  (1895); 
  Moore, 
  J., 
  and 
  Hole 
  (1902); 
  Culbertson, 
  G. 
  (1903); 
  

   Prosser, 
  Ch. 
  S. 
  (1916). 
  

  

  50 
  Cf. 
  Foerste, 
  Kentucky 
  Geol. 
  Surv., 
  Bull. 
  7, 
  1906. 
  Prosser, 
  Ch. 
  S., 
  Jour. 
  

   Geol., 
  24, 
  1916, 
  pp. 
  465-470. 
  

  

  51 
  Ibid., 
  pp. 
  470-472. 
  Foerste, 
  Jour. 
  Cine. 
  Soe. 
  Nat. 
  Hist., 
  18, 
  p. 
  167, 
  1896. 
  

  

  52 
  Kindle 
  and 
  Taylor, 
  U. 
  S. 
  Geol. 
  Survey, 
  Folio 
  190, 
  pi. 
  25, 
  1913. 
  

  

  53 
  Stauff 
  er, 
  in 
  ' 
  ' 
  Geol. 
  of 
  the 
  Columbus 
  Quadrangle, 
  ' 
  ' 
  Ohio 
  Geol. 
  Surv., 
  

   4th 
  Ser., 
  Bull. 
  14, 
  p. 
  20, 
  1911. 
  According 
  to 
  my 
  own 
  measurements, 
  the 
  

   ripples 
  of 
  the 
  so-called 
  ' 
  l 
  smooth 
  layer 
  ' 
  ' 
  of 
  the 
  Columbus 
  limestone, 
  here 
  

   mentioned, 
  have 
  a 
  wave-length 
  of 
  74 
  cm. 
  and 
  an 
  amplitude 
  of 
  2-5 
  cm. 
  

   Prosser, 
  Joe. 
  cit., 
  pp. 
  472-475 
  (2 
  good 
  photogr.). 
  

  

  54 
  Kindle, 
  Ottawa 
  Naturalist, 
  vol. 
  26, 
  pp. 
  1-3, 
  112. 
  

  

  55 
  Udden, 
  Jour. 
  Geol., 
  vol. 
  24, 
  p. 
  125, 
  1916. 
  

  

  56 
  rp 
  Q 
  ^ 
  e 
  described 
  presently. 
  

  

  57 
  Udden, 
  loc. 
  cit., 
  p. 
  126. 
  

  

  