﻿DEEP- 
  WATER 
  MOLLUSCA—VEllEILL 
  AND 
  BUSH. 
  819 
  

  

  rounded 
  with 
  the 
  "dorsal 
  margin 
  rapidly 
  sloped 
  ; 
  ventral 
  margin 
  broadly 
  

   and 
  evenly 
  rounded; 
  posterior 
  end 
  somewhat 
  obliquely 
  truncated 
  with- 
  

   out 
  any 
  definite 
  boundary, 
  bnt 
  with 
  a 
  distinct 
  depression 
  extending- 
  from 
  

   under 
  tlie 
  beak 
  to 
  about 
  the 
  middle 
  of 
  the 
  posterior 
  margin; 
  postero- 
  

   dorsal 
  margin 
  nearly 
  straight, 
  longer, 
  and 
  sloping 
  less 
  rapidly 
  than 
  the 
  

   anterior. 
  The 
  entire 
  surface 
  is 
  covered 
  with 
  minute, 
  irregular, 
  raised, 
  

   grannies 
  and 
  pretty 
  distinct, 
  but 
  irregular, 
  lines 
  of 
  growth 
  and 
  slightly 
  

   raised, 
  distant, 
  thin, 
  radiating 
  lines 
  running 
  from 
  the 
  umljo 
  to 
  the 
  

   margin, 
  except 
  on 
  the 
  posterior 
  end 
  where 
  the 
  lines 
  of 
  growth 
  become 
  

   more 
  prominent; 
  these 
  radial 
  lines 
  are 
  however, 
  in 
  many 
  places, 
  rather 
  

   fiiint 
  and 
  seem 
  to 
  consist 
  mainly 
  of 
  the 
  thin, 
  brownish 
  epidermis, 
  which 
  

   is 
  lacking 
  in 
  certain 
  parts. 
  Minute 
  grains 
  of 
  sand 
  and 
  shells 
  of 
  Foram- 
  

   inifera 
  are 
  firmly 
  adherent 
  to 
  the 
  surface, 
  mainly 
  along 
  the 
  radial 
  

   lines, 
  and 
  especially 
  posteriorly. 
  The 
  interior 
  is 
  white, 
  lustrous 
  and 
  

   bnt 
  slightly 
  nacreous. 
  Muscular 
  and 
  pallial 
  scars 
  indistinct. 
  The 
  

   hinge-margin 
  is 
  thin 
  ; 
  in 
  the 
  left 
  valve 
  the 
  anterior 
  border 
  is 
  somewhat 
  

   thickened 
  in 
  the 
  lunular 
  area 
  and 
  terminates 
  abruptly 
  in 
  a 
  rounded, 
  

   tooth-like 
  shoulder 
  just 
  under 
  the 
  beak; 
  the 
  posterior 
  margin 
  shows 
  a 
  

   slightly 
  raised 
  elongated, 
  roughened 
  area 
  for 
  the 
  attachment 
  of 
  the 
  

   resilium, 
  commencing 
  under 
  the 
  beak 
  and 
  runniTig 
  back 
  for 
  some 
  dis- 
  

   tance 
  within 
  the 
  margin, 
  on 
  its 
  nearly 
  vertical 
  inner 
  surface, 
  so 
  that 
  it 
  

   is 
  scarcely 
  visible 
  in 
  a 
  front 
  view. 
  Ossicle 
  not 
  observed. 
  Ligament 
  

   very 
  thin, 
  occupying 
  a 
  groove 
  along 
  the 
  posterior 
  margin. 
  

  

  Length, 
  19 
  mm.; 
  height, 
  13 
  mm.; 
  breadth, 
  9 
  mm.; 
  from 
  the 
  beak 
  to 
  

   the 
  antero-dorsal 
  angle, 
  7 
  mm.; 
  to 
  the 
  postero-dorsal 
  angle, 
  12 
  mm. 
  

  

  One 
  valve 
  (No. 
  525(51 
  ), 
  station 
  2492, 
  N. 
  lat. 
  45° 
  22', 
  W. 
  long. 
  58° 
  

   43' 
  45", 
  in 
  75 
  fothoms, 
  1885. 
  

  

  This 
  si)ecies 
  is 
  allied 
  to 
  L. 
  arenosa 
  (Moller) 
  with 
  which 
  it 
  agrees 
  very 
  

   closely 
  in 
  the 
  character 
  of 
  the 
  external 
  surface 
  and 
  structure 
  of 
  the 
  

   hinge. 
  It 
  difiers 
  in 
  its 
  longer, 
  more 
  ovate 
  form, 
  in 
  its 
  more 
  produced 
  

   anterior 
  end, 
  and 
  in 
  its 
  less 
  swollen 
  umbo. 
  

  

  Family 
  PANDORID.F. 
  

  

  CLIDIOPHORA 
  INORNATA, 
  new 
  species. 
  

  

  (Plate 
  XCV, 
  figs. 
  5, 
  6.) 
  

  

  Shell 
  small, 
  much 
  compressed, 
  very 
  inequilateral, 
  posterior 
  end 
  nar- 
  

   rowed, 
  somewhat 
  accnminate, 
  the 
  right 
  valve 
  fiat 
  or 
  slightly 
  convex 
  

   and 
  the 
  left 
  valve 
  a 
  little 
  swollen. 
  Umbos 
  not 
  prominent; 
  beaks 
  small 
  

   and 
  appressed. 
  The 
  antero-dorsal 
  margin 
  is 
  slightly 
  convex 
  and 
  

   slopes 
  rapidly 
  to 
  the 
  bluntly 
  rounded 
  anterior 
  end; 
  the 
  ventral 
  margin 
  

   is 
  broadly 
  rounded 
  and 
  slightly 
  prominent, 
  considerably 
  behind 
  the 
  

   middle, 
  beyond 
  which 
  it 
  is 
  incurved 
  to 
  meet 
  the 
  i^osterior 
  rostral 
  

   angulation; 
  the 
  posterior 
  end 
  is 
  produced 
  into 
  a 
  short, 
  narrow, 
  sub- 
  

   truncated, 
  slightly 
  ui)turned 
  rostrum, 
  its 
  lower 
  angle 
  formed 
  by 
  a 
  some- 
  

   what 
  i)romiuent, 
  radial 
  rib 
  or 
  ridge, 
  extending 
  from 
  the 
  beak 
  (on 
  the 
  

  

  