﻿N0.1139. 
  DEEP-WATER 
  MOLLUSCA—VERBTLL 
  AND 
  BUSH. 
  851 
  

  

  The 
  Ledidse, 
  as 
  here 
  understood, 
  were 
  divided 
  into 
  five 
  subfamih'es 
  by 
  

   Fischer, 
  namely 
  : 
  

  

  (1) 
  CucullellintB 
  = 
  Ctenodontidse 
  Dall 
  + 
  PaUeoneilo 
  and 
  Cardiolaria; 
  

   (2) 
  Sareptinne 
  (for 
  iS'arej^/ti 
  only); 
  (3) 
  Ledinoe; 
  (4) 
  Malletiuai 
  (including 
  

   Tindaria)', 
  (5) 
  Lyrodesmatinae 
  (for 
  ancient 
  fossil 
  forms 
  Vike 
  Lyrodesma, 
  

   but 
  including- 
  the 
  living 
  genus 
  Phaseolns 
  or 
  Silicula). 
  An 
  additional 
  

   group 
  was 
  formed 
  for 
  some 
  other 
  doubtful 
  fossil 
  genera. 
  The 
  second 
  

   of 
  these 
  groups 
  is 
  not 
  well 
  founded, 
  for 
  Sarepta 
  agrees 
  closely 
  with 
  

   Yoldittf 
  except 
  in 
  the 
  alleged 
  absence 
  of 
  a 
  pallial 
  sinus, 
  but 
  its 
  gaping 
  

   shell 
  indicates 
  a 
  siphon 
  tube. 
  The 
  fourth 
  should 
  not 
  include 
  Tindaria, 
  

   which 
  lacks 
  the 
  pallial 
  sinus 
  and 
  siphon 
  tubes 
  characteristic 
  of 
  the 
  

   rest 
  of 
  the 
  group 
  and 
  should 
  be 
  taken 
  as 
  the 
  type 
  of 
  a 
  new 
  subfamily. 
  

   The 
  fifth 
  should 
  not 
  include 
  Phaseolus, 
  which 
  differs 
  widely 
  from 
  the 
  

   fossil 
  forms 
  and 
  belongs 
  in 
  the 
  Ledin;p, 
  The 
  other 
  genera 
  of 
  this 
  

   group 
  are 
  referred 
  to 
  TrigoniadiB 
  by 
  other 
  authors, 
  and 
  that 
  would 
  

   seem 
  to 
  be 
  a 
  more 
  correct 
  arrangement. 
  

  

  Family 
  NUCULID.E. 
  

  

  NUCULINA 
  d'Orbigny, 
  184S. 
  

  

  Pleurodon 
  S. 
  Wood, 
  1840. 
  

  

  NucuVma 
  d'Orbigny, 
  1845. 
  

  

  NucineUa 
  S. 
  Wood, 
  1848. 
  

  

  NucnUna 
  Verrill 
  aud 
  Bush, 
  Amer. 
  Journ. 
  Sci., 
  Ill, 
  pp. 
  .53, 
  .59, 
  January, 
  1897. 
  

  

  We 
  have 
  included 
  Nuculina 
  in 
  the 
  Nuculidne 
  with 
  some 
  doubt, 
  

   because 
  authors 
  differ 
  as 
  to 
  its 
  structure. 
  Some 
  state 
  that 
  its 
  liga- 
  

   ment 
  is 
  wholly 
  external 
  and 
  others 
  to 
  the 
  contrary. 
  Fischer 
  places 
  it 
  

   in 
  the 
  Arcidie, 
  near 
  Limopsis, 
  but 
  it 
  has 
  no 
  ligamental 
  area. 
  

  

  Mr. 
  Dall 
  kindly 
  forwarded 
  to 
  us 
  excellent 
  unpublished 
  figures 
  of 
  two 
  

   American 
  species 
  of 
  this 
  genus. 
  In 
  these 
  the 
  thickened 
  ligament 
  is 
  

   external 
  to 
  the 
  hinge-plate, 
  on 
  the 
  end 
  of 
  the 
  shell 
  which 
  is 
  destitute 
  

   of 
  a 
  lateral 
  tooth, 
  and 
  is 
  the 
  shorter 
  (posterior?). 
  The 
  beaks 
  turn 
  

   toward 
  this 
  end. 
  Mr. 
  Dall 
  states 
  that 
  the 
  shells 
  are 
  not 
  distinctly 
  

   nacreous 
  within. 
  

  

  The 
  following 
  are 
  some 
  of 
  the 
  known 
  species 
  : 
  

  

  N. 
  miliar 
  is 
  Deshayes; 
  N. 
  ovalis 
  S. 
  Wood; 
  JV. 
  calabra 
  Seguenza, 
  

   fossil; 
  N. 
  munita 
  Carpenter, 
  from 
  the 
  Catalin 
  Islands; 
  3'. 
  sulcata 
  A. 
  

   Adams, 
  from 
  Korean 
  Straits; 
  N. 
  adamsi 
  Dall, 
  from 
  Florida 
  and 
  the 
  

   West 
  Indies. 
  

  

  NUCULA 
  Lamarck, 
  1799. 
  

  

  Nucula 
  Lamarck, 
  Prodrome 
  d'une 
  Nouv. 
  cl. 
  des 
  Coqiiilles, 
  i>. 
  87, 
  No. 
  104, 
  1799. 
  

   Nuculana 
  Link, 
  Besclir. 
  Rost. 
  Samnil., 
  p. 
  15.5, 
  1807 
  (not 
  of 
  Adams, 
  1858, 
  nor 
  of 
  

  

  Harris, 
  1897). 
  

   Nucula 
  Dall, 
  Bull. 
  Mus. 
  Comp. 
  Zool., 
  XII, 
  p. 
  245, 
  1886. 
  

  

  Type. 
  — 
  Niicula 
  nucleus 
  Lamarck. 
  

  

  Nuculana 
  (Link) 
  was 
  an 
  exact 
  synonym 
  or 
  variant 
  of 
  Nucula, 
  of 
  

   earlier 
  date, 
  as 
  the 
  descrijjtion 
  plainly 
  shows. 
  There 
  was, 
  therefore. 
  

  

  