﻿f^34 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM. 
  vol.xx. 
  

  

  CHLAMYS 
  BENEDICTI 
  Verrill 
  and 
  Bush. 
  

   (Plate 
  LXXXIV, 
  ligs. 
  1, 
  2.) 
  

  

  ChlamiiK 
  heiietlirti 
  Vkuhili, 
  aurt 
  Husii, 
  in 
  Vkkiull, 
  Trans. 
  Conn. 
  Acad., 
  X.p]). 
  71, 
  

   91. 
  1<S07. 
  

  

  Shell 
  small, 
  higher 
  than 
  long; 
  anterior 
  auricle 
  much 
  larger 
  than 
  the 
  

   posterior, 
  Avitli 
  a 
  deep 
  byssal 
  notch 
  in 
  the 
  lower 
  or 
  right 
  valve. 
  The 
  

   dorsal 
  margin 
  is 
  straight 
  and 
  but 
  slightly 
  oblique; 
  the 
  posterior 
  auricle 
  

   in 
  the 
  right 
  valve 
  is 
  decidedly 
  angular, 
  with 
  its 
  outer 
  end 
  slightly 
  

   incurved 
  aud 
  serrated 
  by 
  the 
  termination 
  of 
  the 
  radial 
  ribs; 
  the 
  ante- 
  

   rior 
  auricle 
  is 
  considerably 
  prolonged, 
  angulated 
  at 
  the 
  upper 
  corner, 
  

   obtusely 
  rounded 
  at 
  the 
  end 
  and 
  dee])ly 
  notched 
  where 
  it 
  joins 
  the 
  

   main 
  shell; 
  it 
  has 
  four 
  strongly 
  marked 
  radiating 
  ribs, 
  besides 
  the 
  

   dorso-marginal 
  fold; 
  below 
  these 
  there 
  is 
  a 
  slightly 
  concave 
  space 
  cor- 
  

   responding 
  to 
  the 
  byssal 
  notch; 
  on 
  the 
  body 
  of 
  the 
  shell 
  there 
  are 
  

   from 
  four 
  to 
  seven 
  sharp 
  serrations 
  akmg 
  the 
  lower 
  margin 
  of 
  the 
  

   notch. 
  In 
  the 
  upper 
  valve 
  the 
  anterior 
  auricle 
  is 
  broad 
  and 
  decidedly 
  

   angular, 
  the 
  dorsal 
  and 
  outer 
  margins 
  forming 
  less 
  than 
  a 
  right 
  angle; 
  

   its 
  surface 
  is 
  covered 
  with 
  five 
  or 
  six 
  strong 
  radiating 
  ribs 
  decussated 
  

   by 
  more 
  numerous, 
  finer, 
  concentric 
  raised 
  lines. 
  The 
  anterior 
  and 
  

   posterior 
  margins 
  of 
  the 
  body 
  of 
  the 
  shell 
  slope 
  abont 
  equally 
  and 
  form 
  

   an 
  acute 
  angle; 
  the 
  ventral 
  margin 
  forms 
  a 
  regular 
  semicircular 
  curve. 
  

   The 
  entire 
  surface 
  in 
  both 
  valves 
  is 
  crossed 
  by 
  strongly 
  raised, 
  rather 
  

   close, 
  radiating 
  ribs 
  separated 
  by 
  rather 
  wide, 
  deep 
  grooves 
  and 
  are 
  

   decussated 
  by 
  regular, 
  raised, 
  concentric 
  lines, 
  which 
  are 
  scarcely 
  appar- 
  

   ent 
  on 
  the 
  ribs, 
  except 
  on 
  very 
  young 
  shells, 
  but 
  there 
  are 
  rather 
  

   strong, 
  elevated, 
  spine-like 
  points 
  arranged 
  along 
  the 
  ribs 
  in 
  pretty 
  

   regular, 
  concentric 
  lines, 
  especially 
  near 
  the 
  margins; 
  these 
  become 
  

   higher 
  and 
  more 
  pointed 
  anteriorly 
  and 
  are 
  freipiently 
  nearly 
  obsolete 
  

   in 
  the 
  middle 
  portion 
  of 
  the 
  lower 
  valve; 
  the 
  ribs 
  project 
  at 
  the 
  mar- 
  

   gin 
  as 
  blunt 
  ijoints 
  or 
  serrations; 
  on 
  the 
  inner 
  surface 
  there 
  are 
  radial 
  

   grooves 
  corresponding 
  to 
  the 
  external 
  ribs. 
  The 
  hinge-margin 
  is 
  thin, 
  

   with 
  a 
  slender 
  ligamental, 
  submarginal 
  groove 
  and 
  a 
  small, 
  triangular 
  

   resilial 
  pit 
  in 
  the 
  center. 
  The 
  color 
  is 
  variable; 
  the 
  single 
  valve 
  from 
  

   station 
  2571 
  is 
  uniform 
  lemon 
  yellow; 
  those 
  from 
  the 
  other 
  locality 
  ai-e 
  

   chestnut 
  or 
  reddish 
  brown 
  and 
  variegated 
  with 
  paler 
  and 
  sometimes 
  

   white 
  blotches. 
  

  

  Lengtli 
  of 
  the 
  largest 
  specimen, 
  5.5 
  mm.; 
  li»eight, 
  6 
  mm.; 
  length 
  of 
  

   dorsal 
  margin, 
  4 
  mm. 
  

  

  A 
  few 
  live 
  young 
  specimens, 
  among 
  Foraminifera, 
  stations 
  23G9 
  to 
  

   2374, 
  in 
  25 
  to 
  27 
  fathoms, 
  and 
  a 
  single 
  valve, 
  station 
  2571, 
  in 
  1,350 
  

   fathoms, 
  1885. 
  

  

  This 
  species 
  is 
  a 
  typical 
  Chlamyfi, 
  allied 
  to 
  C. 
  varia 
  of 
  Europe, 
  but 
  

   when 
  compared 
  with 
  young 
  of 
  that 
  species 
  of 
  the 
  same 
  size 
  the 
  radial 
  

   ribs 
  are 
  found 
  to 
  be 
  fewer 
  and 
  coarser, 
  and 
  there 
  are 
  other 
  differences 
  

   which 
  render 
  it 
  probably 
  that 
  they 
  are 
  distinct. 
  It 
  differs 
  from 
  the 
  

   young 
  of 
  C. 
  idandiva 
  in 
  the 
  number 
  of 
  ribs 
  and 
  shape 
  of 
  the 
  auricles. 
  

  

  