﻿82 
  PROCEEDINGS 
  OF 
  THE 
  MALACOLOGICAL 
  SOCIETY. 
  

  

  aside 
  all 
  rules 
  of 
  nomenclature 
  and 
  substituted 
  Lovellia 
  for 
  the 
  older 
  

   name 
  of 
  Raeta, 
  a 
  method, 
  needless 
  to 
  say, 
  which 
  was 
  subsequently 
  

   ignored 
  by 
  all 
  conchologists. 
  

  

  At 
  the 
  time 
  of 
  description 
  this 
  author 
  characterized 
  a 
  fossil 
  form 
  

   of 
  Lovellia 
  under 
  the 
  name 
  of 
  L. 
  consolrina, 
  which 
  had 
  been 
  

   discovered 
  in 
  the 
  Miocene 
  (Helvetian) 
  of 
  Switzerland. 
  Although 
  no 
  

   dental 
  information 
  was 
  given, 
  he 
  noted 
  the 
  condition 
  of 
  the 
  pallial 
  

   sinus 
  as 
  sinu 
  pallii 
  depresso 
  profimdo, 
  which 
  in 
  connexion 
  with 
  the 
  

   shell's 
  contour 
  enabled 
  him 
  to 
  recognize 
  its 
  close 
  affinity 
  to 
  Say's 
  

   Lutraria 
  canaliculata, 
  and 
  therefore 
  it 
  should 
  have 
  been 
  designated 
  

   Raeta. 
  

  

  Further 
  forms 
  of 
  Raeta 
  include 
  R. 
  gihhosa, 
  Gabb,^ 
  from 
  the 
  Upper 
  

   Tertiaries 
  (= 
  Pliocene 
  of 
  Grzybowski*) 
  of 
  Northern 
  Peru, 
  and 
  

   Conrad's^ 
  R. 
  alta 
  (= 
  erecta, 
  Conrad) 
  from 
  the 
  United 
  States 
  Miocene, 
  

   as 
  also 
  R. 
  riitimeyeri 
  of 
  Mayer-Eymar,"* 
  from 
  the 
  Swiss 
  Eocene 
  

   (Bartonian), 
  all 
  of 
  which 
  records 
  furnish 
  evidence 
  that 
  that 
  genus 
  

   originated 
  in 
  Eocene 
  times, 
  and 
  thence 
  existed 
  through 
  the 
  later 
  

   Tertiary 
  epoch 
  on 
  to 
  the 
  seas 
  of 
  the 
  present 
  day. 
  So 
  far 
  as 
  is 
  

   known 
  the 
  new 
  genus 
  Raetomya 
  is 
  restricted 
  to 
  the 
  African 
  Eocene 
  

   deposits, 
  having 
  been 
  first 
  found 
  in 
  Egypt 
  and 
  now 
  in 
  Southern 
  

   Nigeria. 
  

  

  Family 
  PtAETOMYID^. 
  

  

  Raetomya 
  scuwiciNFtrRTHi 
  (Mayer-Eymar). 
  

  

  Lovellia 
  schiceinfurthi, 
  Mayer-Eymar, 
  Journ. 
  de 
  Conch., 
  ser. 
  iir, 
  

  

  vol. 
  xxvii, 
  1887, 
  pp. 
  320-2, 
  pi. 
  xi, 
  fig. 
  6. 
  

   Raeta 
  schweinfurthi, 
  Oppenheim, 
  Palgeontographica, 
  vol. 
  xxx, 
  pt. 
  iii, 
  

   1906, 
  pp. 
  190, 
  191, 
  pi. 
  xix, 
  fig. 
  1, 
  text-fig. 
  17. 
  

  

  The 
  Nigerian 
  specimens 
  referred 
  to 
  this 
  species, 
  hitherto 
  only 
  

   known 
  from 
  the 
  Egyptian 
  Eocene, 
  vary 
  considerably 
  in 
  size, 
  the 
  

   smallest 
  showing 
  a 
  length 
  and 
  height 
  respectively 
  of 
  25 
  and 
  20 
  mm., 
  

   while 
  one 
  of 
  maximum 
  size, 
  a 
  natural 
  cast 
  with 
  united 
  and 
  closed 
  

   valves, 
  measures 
  113 
  by 
  75 
  mm. 
  ; 
  the 
  dimensions 
  of 
  the 
  type 
  being 
  

   65 
  by 
  54 
  mm. 
  

  

  The 
  chief 
  features 
  of 
  interest 
  of 
  this 
  Pelecypod 
  are 
  the 
  very 
  

   inoerjuilateral 
  and 
  obliquely 
  gibbose 
  valves; 
  the 
  thin 
  test 
  with 
  its 
  

   sculpture 
  of 
  more 
  or 
  less 
  regular 
  concentric 
  ridges; 
  the 
  narrow, 
  

   elevated 
  uinbonal 
  regions 
  and 
  their 
  laterally 
  approximate 
  incurved 
  

   beaks; 
  the 
  possession 
  of 
  an 
  elongate, 
  depressed, 
  anterior 
  end 
  region, 
  

   slightly 
  concave 
  above 
  and 
  rounded 
  at 
  extremity, 
  while 
  the 
  posterior 
  

   side 
  is 
  short, 
  wide, 
  marginally 
  compressed, 
  reflected, 
  and 
  slightly 
  

   gaping; 
  pallial 
  sinus 
  widely 
  arcuate; 
  hinge-plate 
  small 
  with 
  an 
  

   anterior 
  lamellar 
  tooth 
  parallel 
  to 
  the 
  margin, 
  as 
  well 
  as 
  an 
  oblique 
  

   and 
  strongly 
  lamellar 
  posterior 
  tooth 
  ; 
  no 
  cardinal 
  teeth 
  referred 
  to. 
  

  

  ^ 
  American 
  Journ. 
  Conch., 
  vol. 
  v, 
  1869, 
  p. 
  30, 
  and 
  Journ. 
  Acad. 
  Nat. 
  Sci. 
  

  

  Philadelphia, 
  N.S., 
  vol. 
  viii, 
  pt. 
  iii, 
  1877, 
  pi. 
  xxxv, 
  fig. 
  8, 
  p. 
  333. 
  

   2 
  Neues 
  Jahrb. 
  Beil.-Band, 
  vol. 
  xii, 
  1899, 
  p. 
  640. 
  

   ' 
  Appendix 
  to 
  Kerr's 
  Eept. 
  Geol. 
  Surv. 
  North 
  Carolina, 
  vol. 
  i, 
  1875, 
  p. 
  19, 
  

  

  , 
  pi. 
  iii, 
  fig. 
  3. 
  

   * 
  Beitr. 
  Geol. 
  Karte 
  Schweiz, 
  vol. 
  xxiv, 
  pt. 
  ii, 
  1887, 
  p. 
  44, 
  pi. 
  iii, 
  fig. 
  18. 
  

  

  