﻿824 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM. 
  

  

  distinctly 
  crenulated 
  along 
  the 
  prominent 
  ventral 
  edge, 
  the 
  crennla- 
  

   tions 
  corresponding 
  to 
  the 
  external 
  grooves 
  and 
  ridges, 
  but 
  at 
  the 
  ends 
  

   it 
  is 
  smooth. 
  There 
  is 
  often 
  a 
  distinct, 
  median 
  internal 
  groove, 
  extend- 
  

   ing 
  from 
  near 
  the 
  beak 
  to 
  the 
  middle 
  of 
  the 
  ventral 
  margin, 
  bordered 
  

   on 
  each 
  side 
  by 
  a 
  distinct 
  raised 
  ridge, 
  sometimes 
  having 
  an 
  additional 
  

   groove 
  on 
  their 
  outer 
  sides. 
  The 
  hinge-margin 
  is 
  rather 
  thin, 
  nearly 
  

   straight, 
  and 
  a 
  little 
  excavated 
  or 
  incurved 
  along 
  the 
  ligamental 
  pit; 
  on 
  

   each 
  side 
  and 
  considerably 
  within 
  the 
  margin 
  there 
  is 
  a 
  small 
  triangnlar 
  

   buttress 
  or 
  shelf-like 
  process 
  extending 
  to 
  the 
  anterior 
  and 
  posterior 
  

   margins 
  as 
  in 
  the 
  allied 
  species, 
  but 
  rather 
  larger 
  than 
  usual. 
  

  

  Length 
  of 
  one 
  of 
  the 
  largest 
  species, 
  6 
  mm.; 
  height, 
  9.0 
  mm.; 
  thick- 
  

   ness, 
  about 
  5 
  mm.; 
  length 
  of 
  hinge-margin, 
  3.6 
  mm. 
  

  

  A 
  number 
  of 
  separate 
  valves, 
  station 
  2265, 
  N. 
  lat. 
  37° 
  7' 
  40", 
  W. 
  

   long. 
  740 
  35' 
  40", 
  in 
  70 
  fathoms, 
  1884. 
  

  

  This 
  species 
  is 
  allied 
  to 
  Limatula 
  suhovata 
  (Jeffreys) 
  Smith,' 
  which 
  

   is 
  distinguished 
  by 
  its 
  shorter 
  hinge-margin, 
  more 
  contracted 
  form, 
  

   with 
  stronger 
  and 
  higher 
  radial 
  ribs 
  and 
  well-marked 
  median 
  sulcus. 
  

   It 
  also 
  lacks 
  the 
  incurvature 
  of 
  the 
  margins 
  below 
  the 
  angles 
  of 
  the 
  

   hinge. 
  

  

  LIMATULA 
  NODULOSA, 
  new 
  species. 
  

  

  Shell 
  small, 
  nearly 
  equilateral, 
  vertically 
  ovate, 
  narrowed 
  above, 
  with 
  

   a 
  comi)aratively 
  short, 
  straight, 
  hinge-margin. 
  Umbos 
  prominent, 
  a 
  

   little 
  compressed. 
  Beaks 
  small, 
  a 
  little 
  prominent, 
  directly 
  incurved. 
  

   Surface 
  covered 
  with 
  radial 
  ribs 
  which 
  are 
  very 
  fine 
  and 
  even 
  on 
  the 
  

   anterior 
  and 
  posterior 
  ends, 
  but 
  in 
  the 
  middle 
  region, 
  become 
  much 
  

   stronger 
  and 
  are 
  rendered 
  nodulose 
  by 
  strongly 
  marked, 
  raised, 
  concen- 
  

   tric 
  lines 
  and 
  grooves. 
  The 
  two 
  median 
  ones 
  are 
  much 
  stronger 
  than 
  

   the 
  others 
  and 
  are 
  separated 
  by 
  a 
  distinct 
  median 
  sulcus. 
  The 
  inner 
  

   surface 
  is 
  marked 
  by 
  radial 
  ridges 
  and 
  grooves 
  of 
  which 
  the 
  median 
  ones 
  

   are 
  much 
  the 
  stronger; 
  inner 
  margin 
  crenulated 
  ventrally 
  by 
  the 
  ends, 
  

   of 
  the 
  ribs 
  and 
  grooves. 
  Ligamental 
  area 
  diamond 
  shape 
  with 
  a 
  small, 
  

   short, 
  rhomboidal 
  ligament 
  pit 
  in 
  the 
  middle. 
  The 
  hinge-margin 
  forms 
  

   an 
  obtuse 
  angle 
  at 
  each 
  end, 
  the 
  two 
  nearly 
  or 
  quite 
  equal 
  ; 
  internal 
  

   buttress 
  well 
  developed 
  with 
  the 
  inner 
  margin 
  regularly 
  curved 
  and 
  

   continuous 
  across 
  the 
  middle, 
  so 
  as 
  to 
  thicken 
  the 
  hinge 
  in 
  this 
  part. 
  

  

  Length, 
  4.5 
  mm.; 
  height, 
  7 
  mm.; 
  thickness, 
  about 
  4 
  mm.; 
  length 
  of 
  

   the 
  hinge-margin, 
  2 
  mm. 
  

  

  A 
  single 
  valve, 
  among 
  Foraminifera, 
  at 
  station 
  2385, 
  IsT. 
  lat. 
  28° 
  51', 
  

   W. 
  long. 
  88° 
  18', 
  in 
  730 
  fathoms, 
  1885. 
  

  

  This 
  species 
  agrees 
  with 
  L. 
  suhovata 
  (Jeffreys) 
  Smith 
  almost 
  com- 
  

   pletely 
  in 
  size 
  and 
  form, 
  but 
  differs 
  very 
  decidedly 
  in 
  the 
  strong, 
  nodu 
  

   lose, 
  radial 
  ribs 
  which 
  cover 
  the 
  middle 
  portion 
  of 
  the 
  shell. 
  

  

  I 
  

  

  ^ 
  Limaa 
  suhovata 
  Verrill, 
  Notice 
  of 
  Receut 
  Add. 
  to 
  Mar. 
  Invert., 
  Ft. 
  2, 
  Proc 
  IT. 
  S. 
  

   Nat. 
  Mus., 
  Ill, 
  p. 
  402, 
  1881. 
  

  

  