﻿812 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  AIUSEUM. 
  vol.xx. 
  

  

  end 
  of 
  the 
  short 
  rostrum 
  which 
  has 
  a 
  distinct, 
  median, 
  dia{]^onal 
  ridge 
  or 
  

   angulation 
  and 
  another 
  less 
  distinct 
  one 
  at 
  its 
  base. 
  The 
  surface 
  of 
  the 
  

   shell 
  is 
  thickly 
  covered 
  with 
  very 
  numerous, 
  and 
  crowded, 
  concentric, 
  

   more 
  or 
  less 
  irregular, 
  raised 
  lines 
  of 
  growth 
  which 
  give 
  it 
  a 
  finely 
  1am- 
  

   ellose 
  appearance 
  when 
  viewed 
  niider 
  a 
  leus. 
  These 
  lines 
  become 
  more 
  

   crowded, 
  more 
  prominent, 
  and 
  form 
  two 
  sinuous 
  wave-^ 
  in 
  crossing 
  the 
  

   rostrum. 
  Color, 
  in 
  alcohol, 
  white 
  tinged 
  with 
  reddish 
  brown. 
  The 
  

   hiiige-margin 
  is 
  delicate; 
  the 
  right 
  valve 
  has 
  no 
  lateral 
  tooth 
  but 
  

   shows 
  a 
  slight 
  thickening 
  of 
  the 
  posterior 
  margin; 
  the 
  cartilage- 
  pi 
  ate 
  

   is 
  small, 
  ovate, 
  directed 
  backward. 
  

  

  Length, 
  6 
  mm.; 
  height, 
  4.5 
  mm.; 
  breadth, 
  3 
  mm. 
  

  

  One 
  live 
  specimen 
  (No. 
  52544), 
  station 
  2570, 
  N. 
  lat. 
  39° 
  54', 
  W. 
  long. 
  

   G70 
  5' 
  30", 
  in 
  1,813 
  fathoms, 
  1885. 
  

  

  " 
  Porcupine 
  Expedition, 
  1870," 
  off 
  Cape 
  Moudego, 
  in 
  740 
  to 
  1,095 
  

   fathoms. 
  — 
  Jeffreys. 
  

  

  MYONERA 
  LIMATULA 
  Dall. 
  

   (Plate 
  LXXIV, 
  lig. 
  8.) 
  

  

  Neivra 
  Ihnatula 
  Dall, 
  Bull. 
  Mas. 
  Comp. 
  Zool., 
  IX, 
  p. 
  112, 
  1881.— 
  Smith, 
  E. 
  A., 
  

   Report 
  Voy. 
  Challenger, 
  Zool. 
  Lainellibranchiata, 
  XII, 
  p. 
  35, 
  1885. 
  

  

  Mj/onera 
  llmatula 
  Dai^l, 
  Bull. 
  Mus. 
  Comp. 
  Zool., 
  XII, 
  j). 
  304, 
  pi. 
  iii, 
  fig. 
  5, 
  188G; 
  

   Bull. 
  U. 
  S. 
  Nat. 
  MuB., 
  No. 
  37, 
  p. 
  68, 
  pi. 
  in, 
  fig. 
  5, 
  1889. 
  

  

  A 
  single 
  live 
  specimen 
  (Xo. 
  38171) 
  was 
  taken 
  at 
  station 
  2048, 
  N. 
  lat. 
  

   40° 
  2', 
  W. 
  long. 
  68° 
  50' 
  30", 
  in 
  547 
  fathoms, 
  1883. 
  

  

  MYONERA 
  (?) 
  PRETIOSA, 
  new 
  species. 
  

   (PlateLXXVIl, 
  fig.5.) 
  

  

  Shell 
  small, 
  very 
  thin 
  and 
  fragile, 
  nearly 
  transparent, 
  compressed, 
  

   elongate-oval 
  with 
  a 
  well-defined, 
  somewhat 
  elongated 
  rostrum. 
  Umbo 
  

   prominent, 
  scarcely 
  oblique 
  and 
  nearly 
  smooth. 
  The 
  antero-dorsal 
  mar- 
  

   gin 
  is 
  convex, 
  anterior 
  end 
  evenly 
  rounded; 
  ventral 
  margin 
  broadly 
  

   convex, 
  becoming 
  incurved 
  at 
  the 
  base 
  of 
  the 
  rostrum 
  ; 
  postero-dorsal 
  

   margin 
  nearly 
  straight. 
  The 
  antero 
  dorsal 
  region 
  is 
  distinctly 
  exca- 
  

   vated 
  in 
  front 
  of 
  the 
  beaks. 
  The 
  body 
  of 
  the 
  shell 
  is 
  ornamented 
  with 
  

   ten 
  or 
  more 
  thin, 
  distinct, 
  slightly 
  raised, 
  concentric 
  riblets 
  separated 
  

   by 
  much 
  wider 
  interspaces. 
  On 
  the 
  rostrum 
  there 
  are 
  two 
  well-marked 
  

   minutely 
  spinulous 
  keels 
  between 
  which 
  are 
  delicate 
  lines 
  of 
  growth; 
  

   the 
  first 
  runs 
  from 
  the 
  beak 
  quite 
  close 
  to 
  and 
  parallel 
  with 
  the 
  dorsal 
  

   margin; 
  while 
  the 
  second 
  extends 
  from 
  the 
  umbo 
  diagonally 
  across 
  the 
  

   rostum 
  to 
  its 
  lower 
  edge. 
  

  

  Length, 
  6 
  mm.; 
  height, 
  3 
  mm.; 
  breadth, 
  about 
  2 
  mm. 
  

  

  This 
  shell 
  has 
  no 
  very 
  close 
  resemblance 
  to 
  any 
  hitherto 
  described. 
  

  

  One 
  valve, 
  station 
  2655, 
  Is^. 
  lat. 
  27° 
  22', 
  W. 
  long. 
  78° 
  7' 
  30", 
  in 
  330 
  

   fathoms, 
  among 
  Foraminifera, 
  188(). 
  

  

  As 
  but 
  a 
  left 
  valve 
  was 
  found, 
  the 
  true 
  position 
  of 
  this 
  species 
  can 
  

   not 
  be 
  decided. 
  

  

  