﻿854 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM. 
  vol.xx. 
  

  

  NUCULA 
  CANCELLATA 
  Jeffreys. 
  

   (Plates 
  LXXXI, 
  fig. 
  3; 
  LXXXVI, 
  fig. 
  5.) 
  

  

  Nucula 
  cancellata 
  Veurill, 
  Trans. 
  Conn. 
  Acad., 
  VI, 
  pp. 
  231, 
  280, 
  1884; 
  Expl. 
  Alba- 
  

   tross, 
  Report 
  IT. 
  S. 
  Com. 
  Fish 
  and 
  Fisheries 
  for 
  1883, 
  p. 
  576, 
  1885.— 
  Dall, 
  Bull. 
  

   U. 
  S. 
  Nat. 
  Mus., 
  No. 
  37, 
  p. 
  42, 
  1889 
  ; 
  Proc. 
  U. 
  S. 
  Nat. 
  Mus., 
  XII, 
  p. 
  258, 
  1889. 
  

  

  A 
  very 
  abundant 
  species, 
  at 
  forty-four 
  stations, 
  between 
  N. 
  lat. 
  42° 
  

   47', 
  W. 
  long. 
  61° 
  4', 
  and 
  N. 
  lat. 
  37° 
  27', 
  W. 
  long. 
  73° 
  33', 
  in 
  384 
  to 
  2,033 
  

   fathoms, 
  1883-1887. 
  South 
  to 
  oft' 
  Tobago, 
  West 
  Indies, 
  in 
  880 
  fathoms.— 
  

   Dall. 
  

  

  Family 
  LEDID^.^ 
  

  

  LEDA 
  Schumacher, 
  1817. 
  

  

  Leda 
  Verrill 
  and 
  Busii, 
  Amer. 
  Jonrn. 
  Sci., 
  Ill, 
  pp. 
  54, 
  62, 
  .January, 
  1897. 
  

   Nnculana 
  Harris, 
  Cat. 
  British 
  Museum, 
  p. 
  348, 
  1897 
  (not 
  Link, 
  1807). 
  

  

  Type. 
  — 
  Leda 
  rostrata 
  (Montagu, 
  1808). 
  

  

  This 
  genus 
  has 
  been 
  variously 
  extended 
  and 
  restricted 
  by 
  authors, 
  

   and 
  several 
  subgeneric 
  and 
  sectional 
  groups 
  have 
  been 
  proposed. 
  In 
  

   the 
  more 
  extended 
  sense 
  it 
  is 
  scarcely 
  capable 
  of 
  a 
  definition 
  that 
  will 
  

   distinguish 
  it 
  from 
  Yoldia, 
  etc. 
  

  

  We 
  proposed, 
  therefore, 
  to 
  restrict 
  it 
  to 
  the 
  typical 
  species, 
  such 
  as 
  

   L. 
  cuspidata 
  Gould, 
  L. 
  caudata 
  (Donovan), 
  L. 
  pernula 
  (Miiller), 
  L. 
  tenu- 
  

   tsw7cato(Couthouy),andmany 
  others 
  closely 
  related. 
  These 
  have 
  a 
  long, 
  

   tapered, 
  bicarinate 
  rostrum, 
  and 
  well- 
  developed 
  siphon 
  tubes, 
  partially 
  

   united. 
  The 
  palpal 
  tentacles 
  are 
  long, 
  flat, 
  tapered, 
  and 
  arise 
  external 
  

   to 
  the 
  bases 
  of 
  the 
  outer 
  palpi, 
  which 
  are 
  broad 
  with 
  slender, 
  acute, 
  

   posterior 
  tips. 
  

  

  Mr. 
  Harris 
  quotes 
  rostrata 
  Linnaeus 
  as 
  the 
  type 
  of 
  his 
  Nuculana^ 
  but 
  

   no 
  such 
  species 
  occurs 
  until 
  Gmelin's 
  edition, 
  1790; 
  rostrata 
  Chem- 
  

   nitz, 
  1784, 
  used 
  by 
  Schumacher 
  as 
  the 
  type 
  of 
  Leda, 
  is 
  now 
  considered 
  

   the 
  same 
  as 
  fluviatilis 
  Sowerby 
  and 
  also 
  Schroeter, 
  1779; 
  rostrata 
  

   Lamarck, 
  1819, 
  is 
  the 
  same 
  as 
  pernula 
  Miiller, 
  1774 
  or 
  6?, 
  so 
  that 
  in 
  

   using 
  rostrata 
  Montagu, 
  1808, 
  we 
  avoid 
  confusion 
  of 
  names 
  without 
  

   leading 
  to 
  any 
  misunderstanding 
  of 
  the 
  form 
  of 
  the 
  shell, 
  for 
  all 
  of 
  the 
  

   above 
  species 
  have 
  the 
  same 
  rostrated 
  form. 
  

  

  LEDA 
  BUSH 
  I 
  AN 
  A 
  Verrill. 
  

  

  (Plates 
  LXXIX, 
  fig. 
  8; 
  LXXXII, 
  fig. 
  9.) 
  

  

  Leda 
  lushiana 
  Verrill, 
  Trans. 
  Conn. 
  Acad., 
  VI, 
  pp. 
  229,280, 
  1884; 
  Expl. 
  Alba- 
  

   tross, 
  Report 
  U. 
  S. 
  Com. 
  Fish 
  and 
  Fisheries 
  for 
  1883, 
  p. 
  576, 
  1885.— 
  Dall, 
  Bull. 
  

   U. 
  S. 
  Nat. 
  Mus., 
  No. 
  37, 
  p. 
  44, 
  1889. 
  

  

  A 
  few 
  specimens, 
  off 
  Cape 
  Hatteras, 
  North 
  Carolina, 
  in 
  516 
  fathoms, 
  

   1883. 
  South 
  to 
  Florida 
  Straits, 
  in 
  120 
  to 
  516 
  fathoms.— 
  Dall. 
  i 
  

  

  ^ 
  Nuculanidw 
  Harris, 
  Australian 
  Ter. 
  Moll., 
  Cat. 
  British 
  Museum, 
  p. 
  348, 
  1897. 
  

  

  