﻿882 
  PJROCJCKDIXGS 
  OF 
  THE 
  X 
  AT 
  I 
  ON 
  A 
  L 
  MUSEUM. 
  

  

  tliose 
  which 
  precede 
  them 
  and 
  a 
  little 
  different 
  in 
  form. 
  Above 
  the 
  

   teeth 
  there 
  is 
  a 
  distinct 
  and 
  rather 
  deep 
  submarginal 
  groove 
  for 
  the 
  

   ligament 
  ^vhich 
  extends 
  continuously 
  both 
  in 
  front 
  of, 
  and 
  behind 
  the 
  

   beaks. 
  l>ehind 
  the 
  beaks 
  there 
  is 
  a 
  distinct 
  rounded 
  ridge 
  running 
  

   outside 
  of, 
  and 
  i)arallel 
  with 
  the 
  liganiental 
  groove 
  and 
  terminating 
  at 
  

   the 
  distal 
  end 
  of 
  the 
  row 
  of 
  teeth. 
  Pallial 
  line 
  entire; 
  no 
  siphon 
  ; 
  anal 
  

   opening 
  separated, 
  surrounded 
  by 
  about 
  twelve 
  unequal 
  papilla*; 
  else- 
  

   where 
  the 
  open 
  mantle 
  edge 
  is 
  nearly 
  plain; 
  foot 
  large 
  with 
  a 
  crenate 
  

   disk. 
  

  

  Epidermis 
  pale 
  yellowish 
  brown; 
  interior 
  glossy 
  bluish 
  white 
  without 
  

   pearly 
  luster. 
  

  

  Length, 
  8 
  mm.; 
  height, 
  G 
  mm.; 
  thickness, 
  about 
  4.5 
  mm. 
  

  

  A 
  small 
  specimen 
  (3 
  mm. 
  long, 
  2.5 
  mm. 
  high) 
  from 
  station 
  2714, 
  is 
  

   doubtfully 
  referred 
  to 
  this 
  species. 
  Externally 
  it 
  is 
  covered 
  with 
  very 
  

   fine 
  regular, 
  concentric, 
  raised 
  lines 
  and 
  grooves, 
  agreeing 
  well 
  with 
  

   the 
  corresponding 
  uuibonal 
  portion 
  of 
  the 
  type. 
  The 
  epidermis 
  is 
  thin, 
  

   pale 
  straw 
  color. 
  The 
  outline 
  is 
  also 
  similar 
  but 
  the 
  posterior 
  half 
  of 
  

   the 
  shell 
  is 
  relatively 
  a 
  little 
  broader, 
  owing 
  to 
  a 
  slight 
  expansiim 
  of 
  

   the 
  postero-ventral 
  margin. 
  Tlie 
  beaks 
  appear 
  to 
  be 
  relatively 
  less 
  

   prominent. 
  The 
  external 
  ligament 
  is 
  well 
  developed 
  both 
  sides 
  of 
  the 
  

   beaks, 
  and 
  is 
  slightly 
  thickened 
  just 
  under 
  them, 
  and 
  fills 
  a 
  very 
  slight 
  

   notch 
  in 
  the 
  edge 
  of 
  the 
  hinge 
  margin 
  above 
  the 
  teeth. 
  The 
  hinge- 
  

   plate 
  is 
  relatively 
  broad 
  and 
  strong, 
  especially 
  anteriorly. 
  There 
  are 
  

   thirteen 
  posterior 
  and 
  nine 
  anterior 
  teeth, 
  the 
  two 
  series 
  separated 
  by 
  

   a 
  small 
  edentulous 
  space. 
  Some 
  of 
  the 
  distal 
  teeth 
  in 
  the 
  anterior 
  

   series 
  are 
  unusually 
  large 
  and 
  stout 
  and 
  exceed 
  any 
  of 
  those 
  in 
  the 
  

   posterior 
  series. 
  The 
  pallial 
  line 
  is 
  distinct 
  and 
  entire. 
  

  

  One 
  live 
  specimen 
  (station 
  25(!G), 
  Is", 
  lat. 
  37° 
  23', 
  W. 
  long. 
  03° 
  8', 
  in 
  

   2,620 
  fathoms, 
  1885. 
  One, 
  very 
  young, 
  live 
  specimen 
  (station 
  2714), 
  ]Sr. 
  

   lat. 
  38° 
  22', 
  W. 
  long. 
  70° 
  17' 
  30", 
  in 
  1,825 
  fathoms, 
  1880. 
  

  

  This 
  species 
  is 
  remarkable 
  for 
  its 
  thick, 
  firm 
  shell, 
  regular 
  ovate 
  

   form, 
  and 
  very 
  even, 
  concentric 
  sculpture. 
  In 
  form 
  and 
  general 
  

   appearance 
  it 
  resembles 
  some 
  species 
  of 
  Callista. 
  

  

  TINDARIA 
  LATA, 
  new 
  species. 
  

  

  Shell 
  rather 
  thick, 
  somewhat 
  compressed, 
  broad-ovate, 
  equilateral, 
  

   narrowest 
  in 
  front 
  of 
  the 
  beaks, 
  the 
  ])osterior 
  end 
  somewhat 
  produced 
  

   and 
  very 
  broad. 
  Umbos 
  only 
  slightly 
  prominent. 
  Beaks 
  small, 
  rather 
  

   acute, 
  turned 
  directly 
  forward 
  and 
  closely 
  appressed 
  to 
  the 
  margin. 
  

   ISTolunule 
  nor 
  escutcheon. 
  The 
  antero-dorsal 
  margin 
  is 
  nearly 
  straight 
  

   and 
  slopes 
  but 
  little, 
  but 
  becomes 
  a 
  little 
  convex 
  and 
  ])asses 
  insensibly 
  

   into 
  the 
  evenly 
  rounded 
  curvature 
  of 
  the 
  anterior 
  end; 
  the 
  ventral 
  

   margin 
  is 
  very 
  evenly 
  and 
  broadly 
  rounded 
  but 
  the 
  curve 
  recedes 
  as 
  it 
  

   passes 
  backward 
  so 
  that 
  the 
  highest 
  part 
  of 
  the 
  shell 
  is 
  distinctly 
  

   behind 
  the 
  middle; 
  the 
  posterior 
  end 
  is 
  very 
  evenly 
  and 
  broadly 
  

   rounded 
  without 
  any 
  angulation; 
  the 
  postero-dorsal 
  margin 
  is 
  consid- 
  

  

  