﻿212 
  Mr. 
  H. 
  J. 
  Carter 
  on 
  the 
  

  

  a 
  more 
  extended 
  acquaintance 
  with 
  the 
  strata 
  of 
  the 
  Eocene 
  

   series 
  may 
  explain. 
  

  

  With 
  the 
  distinction 
  to 
  which 
  I 
  have 
  alluded, 
  it 
  became 
  

   necessary 
  to 
  establish 
  a 
  separate 
  division 
  for 
  the 
  discoid 
  Fora- 
  

   minifera 
  typified 
  by 
  Orhitolites 
  Mantelli, 
  and 
  this, 
  which 
  I 
  

   proposed 
  in 
  1861 
  (' 
  Annals,' 
  vol. 
  viii. 
  p. 
  328), 
  was 
  done 
  by 
  

   Giimbel 
  seven 
  years 
  afterwards 
  under 
  the 
  name 
  of 
  " 
  Lepido- 
  

   cyclina 
  " 
  (' 
  Beitrage 
  zur 
  Foraminiferen-Fauna 
  der 
  nordalpinen 
  

   Eocangebilde/ 
  Miinchen, 
  1868). 
  In 
  short 
  Giimbel 
  in 
  this 
  

   work 
  has 
  divided 
  d'Orbigny's 
  " 
  Orbitoid.es 
  " 
  into 
  five 
  sub- 
  

   genera, 
  reserving 
  the 
  fifth 
  for 
  the 
  kind 
  typified 
  by 
  my 
  Orhi- 
  

   tolites 
  Mantellij 
  and 
  devoting 
  the 
  rest 
  to 
  that 
  typified 
  by 
  

   Orbitoides 
  papyracea. 
  

  

  Of 
  course 
  the 
  subgeneric 
  name 
  ll 
  Lepidocyclina" 
  would 
  

   thus 
  take 
  the 
  place 
  of 
  " 
  Orhitolites 
  ; 
  " 
  but 
  if 
  it 
  can 
  be 
  reason- 
  

   ably 
  inferred 
  that 
  Orhitolites 
  Mantelli 
  is 
  but 
  an 
  evolutionary 
  

   development 
  of 
  Lamarck's 
  genus 
  "Orhitolites" 
  and 
  evolu- 
  

   tionary 
  doctrine 
  is 
  to 
  have 
  influence 
  on 
  nomenclature, 
  then 
  

   the 
  propriety 
  of 
  introducing 
  a 
  new 
  name 
  for 
  anything 
  coming 
  

   from 
  the 
  latter 
  seems 
  undesirable. 
  It 
  was 
  this 
  that 
  influenced 
  

   both 
  Faujas 
  de 
  St.-Fond 
  and 
  d'Archiac 
  in 
  using 
  the 
  generic 
  

   term 
  " 
  Orhitolites 
  " 
  for 
  this 
  fossil. 
  Hence 
  the 
  term 
  " 
  Orbi- 
  

   toides 
  " 
  might 
  be 
  retained 
  for 
  the 
  kind 
  typified 
  by 
  Orbitoides 
  

   popyracea, 
  and 
  that 
  of 
  Orhitolites 
  for 
  those 
  typified 
  by 
  Orhi- 
  

   tolites 
  Mantelli) 
  while 
  the 
  whole, 
  together 
  with 
  Nummulites, 
  

   might 
  be 
  included, 
  as 
  proposed 
  by 
  Carpenter, 
  in 
  the 
  family 
  

   " 
  Nummulinida" 
  (' 
  Introduction 
  to 
  the 
  Study 
  of 
  Foramini- 
  

   fera,' 
  p. 
  xiv, 
  1862). 
  

  

  1 
  have 
  already 
  adduced 
  reasons 
  based 
  on 
  evolutionary 
  

   views 
  for 
  using 
  the 
  term 
  Orhitolites 
  Mantelli 
  (' 
  Annals,' 
  1888, 
  

   vol. 
  ii. 
  p. 
  442), 
  to 
  which 
  I 
  might 
  add 
  that 
  the 
  papillary 
  

   eminence 
  on 
  Orbitoides 
  media, 
  d'Orbigny, 
  is 
  almost 
  always 
  

   represented 
  on 
  Orhitolites 
  marginalis, 
  Lam. 
  (that 
  is 
  the 
  

   recent 
  species), 
  by 
  an 
  accumulation 
  of 
  shell-substance 
  on 
  

   the 
  centre 
  of 
  the 
  disk 
  possessing 
  an 
  irregularly 
  stellate 
  form, 
  

   whose 
  rays 
  extend 
  for 
  a 
  short 
  distance 
  towards 
  the 
  circum- 
  

   ference, 
  and 
  that, 
  although 
  the 
  cells 
  in 
  most 
  instances 
  do 
  not 
  

   present 
  the 
  foramina 
  on 
  the 
  surface 
  which 
  are 
  observed 
  in 
  

   the 
  cell-divisions 
  of 
  Orbitoides 
  media, 
  d'Orb., 
  in 
  a 
  horizontal 
  

   section 
  of 
  the 
  crust, 
  yet 
  in 
  some 
  from 
  the 
  Red 
  Sea 
  (Suez) 
  in 
  

   my 
  cabinet 
  they 
  are 
  unmistakably 
  present 
  in 
  by 
  far 
  the 
  

   greater 
  number 
  of 
  cells, 
  although 
  in 
  their 
  midst 
  are 
  to 
  be 
  seen 
  

   some 
  which 
  do 
  not 
  possess 
  them. 
  Why 
  they 
  should 
  be 
  so 
  

   generally 
  absent 
  in 
  most 
  specimens 
  may 
  be 
  accounted 
  for 
  by 
  

   the 
  free 
  communication 
  which 
  exists 
  between 
  the 
  interior 
  and 
  

   exterior 
  of 
  the 
  organism 
  through 
  the 
  numerous 
  apertures 
  on 
  

  

  