﻿246 
  JOURNAL 
  OF 
  THE 
  WASHINGTON 
  ACADEMY 
  OF 
  SCIENCES 
  VOL. 
  12, 
  NO. 
  10 
  

  

  Similar 
  conical 
  Foraminifera 
  of 
  Eocene 
  age 
  have 
  commonly 
  been 
  

   called 
  by 
  the 
  generic 
  name 
  Conulites, 
  and 
  Chapman 
  in 
  1902 
  (7, 
  pp. 
  156- 
  

   157, 
  276, 
  pi. 
  8, 
  figs. 
  K, 
  k, 
  text 
  fig. 
  36) 
  called 
  the 
  Egyptian 
  species 
  

   Conulites 
  aegyptiensis 
  . 
  The 
  genus 
  Conulites 
  was 
  described 
  by 
  Carter 
  

   in 
  1861 
  (8, 
  pp. 
  331-332, 
  457-458, 
  pi. 
  15, 
  figs. 
  7, 
  7a-g; 
  9, 
  pp. 
  53-54, 
  

   83-84) 
  for 
  a 
  species 
  of 
  Foraminifera, 
  apparently 
  of 
  middle 
  Eocene 
  

   (Kirthar) 
  age, 
  from 
  western 
  India. 
  According 
  to 
  Carter's 
  descrip- 
  

   tion 
  and 
  figures 
  the 
  Indian 
  specimens 
  have 
  a 
  different 
  structure 
  from 
  

   the 
  Egyptian 
  and 
  West 
  Indian 
  specimens. 
  Blanckenhorn 
  (2, 
  p. 
  433) 
  

   suggested 
  that 
  some 
  of 
  the 
  Foraminifera 
  described 
  by 
  Carter 
  in 
  the 
  

   same 
  papers 
  as 
  Orbitolina 
  are 
  similar 
  to 
  the 
  Egyptian 
  Dictyoconus. 
  

  

  In 
  1904 
  Prever 
  and 
  Silvestri 
  (10, 
  pp. 
  470, 
  477-486, 
  figs. 
  1-5) 
  pro- 
  

   posed 
  the 
  new 
  generic 
  name 
  Chapmania 
  for 
  Patellina 
  egyptiensis 
  on 
  the 
  

   invalid 
  grounds 
  that 
  Dictyoconus 
  was 
  a 
  synonym 
  of 
  Orbitolina, 
  and 
  

   was 
  briefly 
  described 
  and 
  not 
  figured. 
  They 
  described 
  and 
  figured 
  

   under 
  the 
  name 
  of 
  Chapmania 
  aegyptiensis 
  (Chapman) 
  a 
  middle 
  Eocene 
  

   species 
  of 
  Foraminifera 
  from 
  Italy 
  that 
  has 
  a 
  different 
  structure 
  from 
  

   the 
  Egyptian 
  and 
  West 
  Indian 
  specimens. 
  Silvestri 
  (ll) 
  and 
  Airaghi 
  

   (12, 
  p. 
  160; 
  13, 
  pp. 
  182-185, 
  pi. 
  5, 
  figs. 
  1-4) 
  recorded 
  this 
  ItaHan 
  spe- 
  

   cies 
  from 
  several 
  localities. 
  In 
  view 
  of 
  the 
  differences 
  between 
  the 
  

   Egyptian 
  and 
  Italian 
  species 
  Silvestri 
  later 
  (14, 
  15) 
  redescribed 
  the 
  

   Italian 
  species, 
  as 
  Chapmania 
  gassiensis} 
  

  

  In 
  1912 
  Schubert 
  (16) 
  described 
  and 
  figured 
  Coscinolina 
  liburnica 
  

   Stache, 
  a 
  genus 
  and 
  species 
  from 
  basal 
  middle 
  Eocene 
  rocks 
  of 
  the 
  

   Istrian-Dalmatian 
  coast 
  that 
  had 
  been 
  imperfectly 
  described 
  by 
  

   Stache 
  in 
  1875 
  (17). 
  Coscinolina 
  has 
  a 
  more 
  pronounced 
  early 
  spiral 
  

   stage 
  than 
  Dictyoconus 
  or 
  "Chapmania," 
  and 
  was 
  considered 
  by 
  Schu- 
  

   bert 
  as 
  a 
  more 
  primitive 
  type. 
  Coscinolina 
  liburnica 
  has 
  been 
  recorded 
  

   by 
  H. 
  Douville 
  (18, 
  19) 
  from 
  northern 
  Egypt 
  in 
  beds 
  below 
  the 
  horizon 
  

   of 
  Dictyoconus. 
  

  

  The 
  available 
  records 
  show 
  that 
  these 
  conical 
  Eocene 
  Foraminifera, 
  

   Conulites, 
  Dictyoconus, 
  Coscinolina, 
  and 
  the 
  Italian 
  genus 
  called 
  

   Chapmania, 
  are 
  strictly 
  tropical. 
  Their 
  range 
  in 
  latitude 
  is 
  even 
  more 
  

   limited 
  than 
  the 
  range 
  in 
  latitude 
  of 
  the 
  orbitoidal 
  genera 
  Orthophrag- 
  

   mina 
  and 
  Leipdocyclina, 
  which 
  migrated 
  northward 
  to 
  southwestern 
  

   France 
  and 
  to 
  the 
  southern 
  Coastal 
  Plain 
  of 
  the 
  United 
  States. 
  The 
  

   remarkable 
  similarity 
  of 
  the 
  Egyptian 
  and 
  West 
  Indian 
  species 
  of 
  

   Dictyoconus 
  is 
  another 
  example 
  of 
  the 
  striking 
  resemblance 
  of 
  the 
  

  

  ' 
  As 
  Chapmania 
  is 
  a 
  synonym 
  of 
  Dictyoconus, 
  the 
  Italian 
  species 
  should 
  receive 
  a 
  new 
  

   generic 
  name. 
  

  

  