﻿Verrill 
  and 
  Bush 
  — 
  Genera 
  of 
  Ledidce 
  and 
  JSfuculidoe. 
  59 
  

  

  Dall, 
  T. 
  cuneata 
  Smith 
  = 
  T. 
  Smithii 
  Dall, 
  and 
  T. 
  callistiformis 
  

   y. 
  and 
  B.* 
  All 
  except 
  the 
  first 
  two 
  are 
  from 
  American 
  waters. 
  

  

  Subgenus 
  Tindariopsis 
  i 
  nov. 
  Type 
  T. 
  agathida 
  (Dall).f 
  

  

  This 
  division 
  is 
  proposed 
  for 
  those 
  species 
  which 
  have 
  a 
  short 
  

   rostrum, 
  defined 
  by 
  a 
  radial 
  ridge 
  and 
  a 
  furrow. 
  The 
  type 
  has 
  a 
  

   well-marked 
  dorsal 
  ligamental 
  furrow 
  and 
  a 
  small 
  notch 
  or 
  

   " 
  socket 
  " 
  under 
  the 
  beak 
  for 
  a 
  specialized 
  part 
  of 
  the 
  ligament. 
  

  

  It 
  is 
  uncertain 
  whether 
  it 
  has 
  a 
  siphon 
  and 
  pallial 
  sinus. 
  In 
  

   case 
  these 
  are 
  present, 
  it 
  should 
  form 
  a 
  distinct 
  genus 
  and 
  be 
  

   referred 
  to 
  Malletinse. 
  

  

  Analytical 
  table 
  of 
  recent 
  subfamilies, 
  genera, 
  and 
  subgenera 
  of 
  

   Ledidce 
  and 
  Nucididw 
  here 
  adopted. 
  

  

  A. 
  Shell 
  not 
  gaping, 
  short-ovate, 
  subtrigonal, 
  or 
  rounded 
  ; 
  pos- 
  

  

  terior 
  end 
  without 
  a 
  rostrum 
  ; 
  beaks 
  usually 
  curved 
  

   backward 
  ; 
  no 
  siphon 
  tubes 
  nor 
  pallial 
  sinus. 
  

  

  Nuculidse 
  d'Orb. 
  

  

  B. 
  Shell 
  more 
  or 
  less 
  trigonal, 
  usually 
  oblique 
  ; 
  posterior 
  end 
  

  

  usually 
  shorter 
  ; 
  beaks 
  turned 
  backward 
  Nuculinge. 
  

  

  c. 
  Teeth 
  numerous, 
  transverse, 
  v-shaped, 
  forming 
  two 
  con- 
  

   vexly 
  arched 
  or 
  angulated 
  series 
  ; 
  a 
  distinct 
  median 
  

   chondrophore 
  ; 
  no 
  lateral 
  teeth 
  Nucula 
  Lam. 
  

  

  cc. 
  Teeth 
  few, 
  not 
  forming 
  long 
  series 
  ; 
  a 
  long 
  lateral 
  tooth 
  

   in 
  each 
  valve; 
  no 
  median 
  chondrophore 
  Nuculina. 
  

  

  BB. 
  Shell 
  rounded, 
  nearly 
  equilateral 
  ; 
  beaks 
  turned 
  forward 
  ; 
  

   teeth 
  oblique, 
  in 
  two 
  series; 
  ligament 
  in 
  an 
  elongated 
  

   posterior 
  internymphal 
  groove 
  Glominse, 
  nov. 
  

  

  AA. 
  Shell 
  ovate, 
  oblong 
  or 
  lanceolate 
  ; 
  posterior 
  end 
  generally 
  

   the 
  longer 
  and 
  usually 
  more 
  or 
  less 
  rostrated 
  ; 
  siphon 
  

   tubes 
  and 
  pallial 
  sinus 
  generally 
  present 
  Ledidse. 
  

  

  C. 
  Cartilage 
  or 
  resilium 
  present, 
  not 
  closely 
  united 
  with 
  the 
  

  

  external 
  ligament 
  Ledinae. 
  

  

  a. 
  Resilium 
  supported 
  by 
  a 
  definite 
  concave 
  chondrophore 
  

  

  extending 
  inward 
  to 
  or 
  beyond 
  the 
  inner 
  edge 
  of 
  the 
  

   hinge-plate. 
  

  

  b. 
  Shell 
  not 
  gaping 
  unless 
  at 
  the 
  end 
  of 
  the 
  rostrum, 
  

   o. 
  Shell 
  distinctly 
  rostrated 
  and 
  carinated 
  posteriorly. 
  

  

  Leda 
  Schum. 
  (sens, 
  ext.) 
  

  

  * 
  Tindaria 
  callistiformis 
  ; 
  sp. 
  nov. 
  Figures 
  10, 
  20, 
  21. 
  

  

  Shell 
  small, 
  stout, 
  thick, 
  regularly 
  ovate, 
  sculptured 
  with 
  very 
  regular 
  fine 
  con- 
  

   centric 
  grooves. 
  Umbos 
  swollen, 
  beaks 
  prominent, 
  curved 
  strongly 
  inward 
  and 
  

   somewhat 
  forward. 
  Hinge-plate 
  with 
  a 
  continuous 
  series 
  of 
  teeth, 
  about 
  eight 
  

   before 
  and 
  twenty-three 
  behind 
  the 
  beaks. 
  Ligament 
  groove 
  rather 
  deep, 
  sub- 
  

   marginal, 
  both 
  before 
  and 
  behind 
  the 
  beaks. 
  Color 
  pale 
  yellowish 
  brown, 
  intern- 
  

   ally 
  glossy, 
  bluish 
  white. 
  

  

  Length," 
  8 
  ram 
  ; 
  height, 
  6 
  mm 
  ; 
  thickness, 
  about 
  4"5 
  mm 
  . 
  

  

  One 
  living 
  specimen, 
  station 
  2566 
  off 
  Chesapeake 
  Bay, 
  in 
  2620 
  fathoms, 
  1885. 
  

  

  f 
  Malletia 
  [Tindaria) 
  agathida 
  Dall, 
  Proc. 
  U. 
  S. 
  Nat. 
  Mus., 
  xii, 
  p. 
  252, 
  pi. 
  xiii, 
  

   riff. 
  10, 
  1889. 
  

  

  