﻿336 
  ME. 
  E. 
  B. 
  NEWTON 
  ON 
  

  

  19. 
  Phoeaeomya 
  ambigtta, 
  J. 
  Sowerby, 
  1819. 
  

   Lower 
  Oolite 
  (England 
  ; 
  France). 
  Iraony. 
  

  

  20. 
  Ceeohya 
  concenteica, 
  J. 
  de 
  C. 
  Sowerby 
  (sp.), 
  1825. 
  

   Lower 
  Oolite 
  (England; 
  France). 
  Iraony. 
  

  

  21. 
  Oeis 
  (allied 
  to) 
  trigonalis, 
  J. 
  de 
  C. 
  Sowerby 
  (sp.), 
  1824. 
  

   Lower 
  Oolite 
  (England 
  ; 
  France). 
  Iraony. 
  

  

  22. 
  Lecixa 
  Beeeoxa, 
  d"Orbigny, 
  1849. 
  

   Lower 
  Oolite 
  (England 
  ; 
  France). 
  Iraony. 
  

  

  23. 
  Myopsis 
  delates, 
  Phillips 
  (sp.), 
  1829. 
  

   Lower 
  Oolite 
  (Britain). 
  Iraony. 
  

  

  24. 
  Astaete 
  (allied 
  to) 
  angeeata, 
  llorris 
  and 
  Lyeett, 
  1854. 
  

   Lower 
  Oolite 
  (Britain). 
  Iraonj-. 
  

  

  25. 
  Astaete 
  (?) 
  Baeoni, 
  n. 
  sp. 
  (PI. 
  XIY. 
  figs. 
  9-11.) 
  

  

  Description. 
  — 
  Shell 
  equivalve, 
  very 
  inequilateral, 
  elongately 
  ovate, 
  

   thick, 
  tumid 
  ; 
  umbones 
  contiguous 
  and 
  incurved 
  ; 
  lunule 
  small, 
  

   oval; 
  anterior 
  sides 
  short, 
  posterior 
  curved 
  and 
  sharply 
  keeled, 
  

   forming 
  the 
  boundaries 
  to 
  a 
  deeply 
  excavated 
  escutcheon, 
  which 
  

   extends 
  from 
  the 
  umbones 
  to 
  the 
  posterior 
  angle, 
  measuring 
  in 
  its 
  

   greatest 
  width 
  9 
  millim. 
  

  

  Dimensions. 
  — 
  Length 
  = 
  35 
  millim. 
  ; 
  height 
  = 
  29 
  ; 
  breadth 
  = 
  20. 
  

  

  This 
  species 
  resembles 
  the 
  Qyprina 
  boloniensis 
  of 
  de 
  Loriol 
  

   (Mem. 
  Soc. 
  Phys. 
  Geneve, 
  1868, 
  pi. 
  v. 
  figs. 
  9, 
  9a, 
  p. 
  54), 
  but 
  differs 
  

   from 
  it 
  in 
  the 
  greater 
  length 
  and 
  width 
  of 
  the 
  escutcheon-groove, 
  

   which 
  occupies 
  the 
  whole 
  of 
  the 
  dorsal 
  area 
  of 
  the 
  shell 
  ; 
  in 
  de 
  

   Loriol's 
  specimen 
  it 
  extends 
  to 
  within 
  4 
  millim. 
  of 
  the 
  posterior 
  

   angle. 
  

  

  I 
  have 
  placed 
  this 
  species 
  provisionally 
  in 
  the 
  genus 
  Astarte, 
  as 
  

   its 
  dentition 
  is 
  unknown. 
  Certainly 
  it 
  possesses 
  external 
  characters 
  

   more 
  in 
  common 
  with 
  that 
  genus 
  than 
  with 
  Oyprina. 
  

  

  I 
  propose 
  to 
  name 
  this 
  shell 
  Astarte 
  (?) 
  Baroni, 
  in 
  honour 
  of 
  its 
  

   discoverer, 
  the 
  Bev. 
  Bichard 
  Baron. 
  

  

  Lower 
  Oolite. 
  Ankoala. 
  Collected 
  by 
  the 
  Bev. 
  R. 
  Baron. 
  

  

  26. 
  Sphj:ea 
  maeagascariensis, 
  n. 
  sp. 
  (PI. 
  XIY. 
  figs. 
  6-8.) 
  

  

  Description 
  (Bight 
  valve). 
  — 
  Shell 
  equivalve, 
  subequilateral, 
  solid, 
  

   vcntricose 
  ; 
  posterior 
  dorsal 
  and 
  ventral 
  margins 
  rounded, 
  anterior 
  

   dorsal 
  side 
  oblique 
  and 
  deep 
  ; 
  hinge-area 
  massive 
  and 
  arched, 
  

   containing 
  two 
  blunt 
  principal 
  teeth 
  separated 
  by 
  a 
  pit, 
  the 
  margin 
  

   of 
  which 
  forms 
  a 
  slight 
  lunular 
  expansion 
  beneath 
  the 
  umbo 
  ; 
  

   posterior 
  tooth 
  transverse, 
  the 
  anterior 
  one 
  longitudinal, 
  with 
  

   a 
  somewhat 
  flattened 
  upper 
  surface 
  : 
  ligament-groove 
  narrow, 
  round 
  

   and 
  prominent 
  ; 
  small 
  pit-markings 
  are 
  present 
  on 
  the 
  posterior 
  

   lateral 
  extremity 
  of 
  the 
  hinge 
  ; 
  surface 
  ornamented 
  with 
  coarse 
  

   concentric 
  furrows. 
  

  

  