﻿848 
  rUOCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM. 
  vol.xx. 
  

  

  The 
  following 
  are 
  described 
  species: 
  

  

  G. 
  nifens 
  Jeffreys, 
  North 
  Atlantic 
  (Europe) 
  and 
  from 
  off 
  Marthas 
  

   Vineyard 
  south 
  to 
  off 
  Rio 
  de 
  la 
  Plata 
  (America); 
  G. 
  jef'reysi 
  Smith; 
  

   G. 
  shnplcx 
  Smith, 
  and 
  G. 
  ina'qmlateraUs 
  Smith, 
  West 
  Indies; 
  (r. 
  japon- 
  

   icns 
  Smith, 
  off" 
  Jai)an. 
  

  

  GLOMUS 
  NITENS 
  Jeffreys. 
  

   (Plato 
  XCVIl, 
  li-.-8. 
  1,2.) 
  

  

  (llomiis 
  nitens 
  Jeffreys, 
  Annals 
  Mag. 
  Nat. 
  Hist., 
  p. 
  433, 
  November, 
  1876 
  ; 
  Proc. 
  

   Zool. 
  iSoc, 
  London, 
  !>. 
  573, 
  pL 
  xlv, 
  fig. 
  .">, 
  June, 
  1879. 
  — 
  Verrill, 
  Trans. 
  Conn. 
  

   Acad.. 
  VI, 
  p. 
  231, 
  1884; 
  Expl. 
  Albatross, 
  Report 
  U. 
  S. 
  Com. 
  Fish 
  and 
  Fisheries 
  

   for 
  1883, 
  p. 
  576, 
  1885.— 
  Smith, 
  E. 
  A., 
  Eepurt 
  Voy. 
  ChaUeiKjer, 
  Zool., 
  Lnnielli- 
  

   branchiata, 
  XIII, 
  p. 
  248, 
  1885.— 
  Ball, 
  Bull. 
  U. 
  S. 
  Nat. 
  Mus., 
  No. 
  37, 
  p. 
  4(), 
  1889.— 
  

   Vkkuill 
  and 
  Bush, 
  Amer. 
  Jouru. 
  Sol., 
  Ill, 
  p. 
  53, 
  figs. 
  1, 
  2, 
  January, 
  1897. 
  

  

  The 
  specimens 
  which 
  we 
  refer 
  to 
  this 
  species 
  agree 
  closely 
  in 
  size 
  and 
  

   form 
  with 
  Jeifreys's 
  figures, 
  but 
  there 
  is 
  in 
  both 
  valves 
  a 
  small 
  submar- 
  

   ginal 
  lateral 
  tooth 
  just 
  beyond 
  the 
  posterior 
  series 
  of 
  teeth, 
  and 
  in 
  the 
  

   riglit 
  valve 
  a 
  similar 
  but 
  less 
  prominent 
  one 
  just 
  beyond 
  the 
  anterior 
  

   series. 
  These 
  are 
  not 
  mentioned 
  in 
  Jeftreys's 
  description. 
  In 
  the 
  pos- 
  

   terior 
  series 
  there 
  are 
  fewer 
  teeth 
  than 
  in 
  his 
  figure 
  and 
  they 
  have 
  an 
  

   acute, 
  oblique, 
  V 
  shaped 
  outline 
  and 
  are 
  but 
  little 
  raised; 
  in 
  the 
  ante- 
  

   rior 
  series 
  there 
  are 
  four 
  larger, 
  obliciue 
  teeth 
  which 
  are 
  not 
  so 
  dis- 
  

   tinctly 
  V-shaped, 
  owing 
  to 
  their 
  oblique 
  position 
  and 
  because 
  the 
  sur- 
  

   face 
  of 
  the 
  hinge-plate 
  is 
  turned 
  downward. 
  The 
  posterior 
  ligament 
  is 
  

   strong, 
  hmg, 
  wedge-shaped, 
  widest 
  distally 
  where 
  it 
  occupies 
  most 
  of 
  

   the 
  width 
  of 
  the 
  hinge 
  plate; 
  the 
  narrow 
  prolongation 
  runs 
  forward 
  

   under 
  the 
  beaks 
  in 
  a 
  narrow 
  groove. 
  There 
  is 
  a 
  thickened, 
  edentulous 
  

   space 
  under 
  the 
  beaks, 
  separating 
  the 
  two 
  series 
  of 
  teeth, 
  which 
  has, 
  

   when 
  highly 
  magnified, 
  a 
  very 
  small, 
  angular 
  notch 
  iu 
  the 
  middle 
  of 
  its 
  

   lower 
  edge, 
  which 
  iu 
  our 
  specimen 
  is 
  filled 
  with 
  what 
  appears 
  like 
  the 
  

   remains 
  of 
  a 
  resilium; 
  there 
  is 
  also 
  a 
  very 
  minute, 
  V-shaped 
  notch 
  in 
  

   the 
  external 
  margin. 
  The 
  beaks 
  turn 
  forward. 
  The 
  i)allial 
  impres- 
  

   sion 
  is 
  rather 
  indistinct, 
  but 
  appears 
  entire. 
  Interior 
  somewhat 
  lus- 
  

   trous, 
  but 
  not 
  at 
  all 
  nacreous. 
  

  

  Two 
  imperfect 
  specimens, 
  at 
  two 
  stations, 
  off" 
  Marthas 
  Vineyard 
  and 
  

   oft' 
  Delaware 
  Bay, 
  in 
  1,544 
  and 
  1,608 
  fathoms, 
  1883 
  and 
  1880. 
  South 
  to 
  

   Rio 
  de 
  la 
  Tlata, 
  in 
  294 
  to 
  1,900 
  fathoms.— 
  Dall 
  and 
  Smith. 
  

  

  REVIEW 
  OF 
  THE 
  GENERA 
  OF 
  LEDID^ 
  AND 
  NUCULID.E 
  OF 
  THE 
  ATLAN- 
  

   TIC 
  COAST 
  OF 
  THE 
  UNITED 
  STATES.' 
  

  

  These 
  families 
  are 
  often 
  united 
  by 
  modern 
  malacologists 
  under 
  a 
  sin- 
  

   gle 
  family 
  (Nuculidie), 
  while 
  others 
  regard 
  them 
  as 
  distinct. 
  They 
  are 
  

   certainly 
  closely 
  related 
  anatomically, 
  as 
  well 
  as 
  by 
  the 
  structure 
  of 
  the 
  

   shell. 
  Thus 
  all 
  the 
  members 
  of 
  both 
  families 
  have 
  a 
  single 
  pair 
  of 
  

  

  ' 
  An 
  abstract 
  of 
  tbe 
  portion 
  of 
  this 
  article 
  relating 
  to 
  these 
  fiimilies 
  was 
  published 
  

   in 
  th(^ 
  American 
  Journal 
  of 
  Science, 
  III, 
  p. 
  51, 
  January, 
  1897. 
  

  

  