﻿in] 
  Special 
  Report 
  No. 
  6 
  : 
  Lignitic 
  Fauna 
  301 
  

  

  of 
  specimens 
  of 
  this 
  genus 
  in 
  rocks 
  from 
  Cretaceous 
  or 
  Tertiary- 
  

   deposits. 
  However, 
  the 
  silvery, 
  scaly 
  character 
  of 
  the 
  semi- 
  

   disintegrated 
  shell 
  is 
  rather 
  noticeable 
  and 
  is 
  apt 
  to 
  attract 
  atten- 
  

   tion 
  and 
  arouse 
  wonderment 
  as 
  to 
  the 
  nature 
  of 
  the 
  animal 
  that 
  

   produced 
  it. 
  It 
  is 
  a 
  distant 
  relative 
  of 
  the 
  pearl 
  oyster. 
  

  

  Localities 
  — 
  I^a 
  Nana 
  bayou, 
  near 
  Many 
  ; 
  S. 
  E. 
  of 
  Sodus, 
  lime- 
  

   stone 
  concretions. 
  

  

  Horizon 
  — 
  Lower 
  Lignitic. 
  

  

  Barbatia 
  cuculloides, 
  var. 
  Plate 
  53, 
  fig. 
  3. 
  

  

  Syn. 
  — 
  Area 
  cuculloides 
  Q^on. 
  , 
  Foss. 
  Shells, 
  Tert. 
  Form., 
  p. 
  37, 
  1833. 
  

   B. 
  cuculloides 
  Har., 
  Bull. 
  Amer. 
  Pal., 
  vol. 
  2, 
  p. 
  239, 
  pi. 
  14, 
  

  

  fig- 
  I, 
  1897- 
  

  

  The 
  members 
  of 
  this 
  division 
  of 
  the 
  Areas 
  are 
  somewhat 
  vari- 
  

   able 
  in 
  form 
  and 
  surface 
  markings, 
  and 
  we 
  have 
  been 
  unable 
  to 
  

   satisfactorily 
  differentiate 
  the 
  Eocene 
  species. 
  In 
  fact 
  the 
  Oli- 
  

   gocene 
  forms 
  from 
  Vicksburg, 
  are 
  perhaps 
  of 
  one 
  and 
  the 
  same 
  

   species 
  with 
  the 
  Eocene. 
  

  

  Localities.— 
  Vq.wA\q.\.o\\, 
  Tex., 
  S. 
  W. 
  ^, 
  S. 
  W. 
  %, 
  S. 
  18. 
  7 
  N., 
  

   10 
  W. 
  Marthaville. 
  . 
  

  

  Horizon. 
  — 
  Lower 
  Lignitic. 
  

  

  Leda 
  aldrichiana, 
  var., 
  Plate 
  53, 
  fig. 
  5. 
  

  

  Syn. 
  — 
  y'oldia 
  aldrichiana 
  Har., 
  Bull. 
  Amer. 
  Pal., 
  vol. 
  2, 
  p. 
  245, 
  

   pi. 
  14, 
  fig. 
  15, 
  June, 
  1897. 
  

   Leda 
  acalaVi2\\. 
  , 
  Tr. 
  Wag. 
  Free 
  Inst. 
  Sci., 
  vol. 
  3, 
  586, 
  

   pi. 
  32, 
  fig. 
  3, 
  Oct. 
  1898. 
  

  

  The 
  Sabinetown 
  specimens 
  when 
  compared 
  with 
  those 
  from 
  

   the 
  type 
  locality. 
  Woods 
  bluff, 
  will 
  be 
  found 
  to 
  be 
  somewhat 
  

   broader 
  posteriorly 
  or 
  comparatively 
  less 
  Ventricose 
  anteriorly 
  

   than 
  those 
  from 
  the 
  last 
  mentioned 
  locality. 
  Yet 
  the 
  distance 
  

   between 
  the 
  localities 
  is 
  doubtless 
  suflficent 
  to 
  account 
  for 
  a 
  con- 
  

   siderable 
  amount 
  of 
  variation. 
  It 
  would 
  certainly 
  be 
  unwise 
  to 
  

   propose 
  a 
  new 
  specific 
  name 
  for 
  these 
  western 
  specimens 
  when 
  

   the 
  differences 
  are 
  confined 
  to 
  general 
  outlines 
  of 
  the 
  shells. 
  

  

  Locality. 
  — 
  Sabinetown, 
  Texas. 
  

  

  Horizon. 
  — 
  Upper 
  Lignitic. 
  

  

  I/cda 
  corpulentoides, 
  var. 
  

   Syn. 
  — 
  Yoldia 
  corp7ileiitoides 
  A.\d., 
  Bull. 
  Amer. 
  Pal., 
  vol. 
  i, 
  p. 
  70, 
  

   pi 
  6, 
  fig. 
  9, 
  9a, 
  1895. 
  

  

  