﻿810 
  PEOCEEDIXGS 
  OF 
  THE 
  N 
  ATI 
  OX 
  A 
  L 
  MUSETM. 
  vol.xx. 
  

  

  CARDIOMYA 
  GLYPTA 
  Bush. 
  

  

  (Plates 
  LXXI, 
  i\g. 
  1; 
  LXXVI, 
  figs. 
  3, 
  7.) 
  

  

  Newra 
  cosiata 
  Bush, 
  Trans. 
  Conn. 
  Acad., 
  VI, 
  p. 
  472, 
  pi. 
  xi.v, 
  fig. 
  21, 
  1885; 
  Expl. 
  

  

  Alhatrosi^, 
  Reiiort 
  U. 
  S. 
  Com. 
  Fish 
  aud 
  Fisheries 
  for 
  1883, 
  p. 
  587, 
  1885; 
  not 
  

  

  Sowerby, 
  1834. 
  

   Cardiomya 
  ortiutissima 
  Dall, 
  Bull. 
  Mns. 
  Comp. 
  Zool., 
  XII, 
  j). 
  296, 
  1886; 
  Bull. 
  U. 
  S. 
  

  

  Nat. 
  Mus., 
  No. 
  37, 
  p. 
  66, 
  pi. 
  xli, 
  fig. 
  21, 
  1889. 
  

  

  A 
  few 
  specimens 
  were 
  found 
  at 
  two 
  stations 
  off 
  Cape 
  Hatteras, 
  iTorth 
  

   Carolina, 
  in 
  48 
  fathoms. 
  South 
  to 
  Guadaloupe, 
  in 
  li 
  to 
  124 
  fathoms. 
  — 
  

   Dall. 
  

  

  In 
  addition 
  to 
  the 
  published 
  description 
  it 
  should 
  be 
  stated 
  that 
  the 
  

   an 
  tero 
  dorsal 
  margin 
  of 
  the 
  right 
  valve 
  rises 
  into 
  a 
  distinct, 
  prominent, 
  

   obtuse 
  lobe 
  in 
  front 
  of 
  the 
  tooth; 
  this 
  lobe 
  overlaps 
  the 
  margin 
  of 
  the 
  

   left 
  valve 
  when 
  the 
  shell 
  is 
  closed. 
  There 
  is 
  a 
  small 
  buttress 
  beneath 
  

   the 
  posterior 
  lateral 
  tooth. 
  One 
  broken 
  valve, 
  considerably 
  larger 
  than 
  

   the 
  type, 
  has 
  in 
  the 
  intervals 
  between 
  the 
  three 
  primary 
  ribs 
  two 
  or 
  

   three 
  small 
  secondary 
  ones; 
  on 
  the 
  anterior 
  end 
  six 
  ribs 
  are 
  visible, 
  of 
  

   which 
  one 
  or 
  two 
  are 
  larger 
  than 
  the 
  rest, 
  so 
  that 
  altogether 
  about 
  thir- 
  

   teen 
  or 
  fourteen 
  ribs 
  can 
  be 
  counted; 
  some 
  of 
  these 
  are, 
  however, 
  very 
  

   small 
  and 
  extend 
  only 
  part 
  way 
  to 
  the 
  umbo; 
  even 
  the 
  largest 
  do 
  not 
  

   extend 
  over 
  the 
  extreme 
  part 
  of 
  the 
  umbo. 
  

  

  Mr. 
  Dall 
  considers 
  this 
  species 
  to 
  be 
  identical 
  with 
  D'Orbigny's 
  orna- 
  

   tissima, 
  but 
  we 
  see 
  no 
  sufficient 
  reason 
  for 
  uniting 
  the 
  two 
  forms. 
  

  

  The 
  name 
  costata 
  was 
  used 
  by 
  Sowerby 
  in 
  1834. 
  

  

  HALONYMPHA 
  STRIATELLA, 
  new 
  species. 
  

  

  (Plates 
  LXXII, 
  figs. 
  2, 
  3; 
  LXXVII, 
  fig. 
  10.) 
  

  

  Shell 
  small, 
  thin, 
  broadly 
  and 
  obliquely 
  ovate, 
  with 
  a 
  narrow, 
  short 
  

   rostrum. 
  Umbo 
  swollen. 
  Beak 
  behind 
  the 
  middle. 
  The 
  antero-dorsal 
  

   margin 
  is 
  broadly 
  and 
  nearly 
  evenly 
  convex 
  ; 
  the 
  anterior 
  end 
  is 
  evenly 
  

   rounded; 
  the 
  ventral 
  margin 
  is 
  broadly 
  convex 
  with 
  a 
  slight 
  incurva- 
  

   ture 
  at 
  the 
  base 
  of 
  the 
  rostrum, 
  which 
  is 
  short, 
  narrow, 
  and 
  obtuse 
  at 
  

   the 
  end; 
  the 
  postero-dorsal 
  margin 
  is 
  strongly 
  concave 
  and 
  slopes 
  

   rapidly. 
  In 
  the 
  region 
  of 
  the 
  umbo 
  the 
  surface 
  is 
  lustrous 
  and 
  nearly 
  

   smooth, 
  but 
  marked 
  with 
  faint, 
  parallel 
  lines 
  ; 
  elsewhere 
  it 
  is 
  closely 
  

   covered 
  with 
  very 
  regular, 
  fine, 
  raised 
  concentric 
  lines 
  separated 
  by 
  

   incised 
  lines 
  of 
  about 
  the 
  same 
  width 
  or 
  narrower; 
  on 
  the 
  rostrum 
  

   there 
  is 
  a 
  faint 
  diagonal 
  ridge 
  posterior 
  to 
  which 
  the 
  concentric 
  lines 
  

   are 
  irregular. 
  The 
  interior 
  surface 
  is 
  smooth 
  and 
  lustrous 
  but 
  the 
  

   external 
  lines 
  show 
  through 
  by 
  transparency. 
  In 
  the 
  right 
  valve 
  there 
  

   is 
  a 
  small, 
  sharp, 
  triangular 
  tooth 
  ijrojecting 
  inward 
  with 
  a 
  very 
  small 
  

   cartilage-pit 
  in 
  front 
  of 
  and 
  confluent 
  with 
  it; 
  slightly 
  farther 
  forward 
  

   there 
  is 
  another 
  small, 
  slender 
  tooth 
  rising 
  nearly 
  parallel 
  with 
  the 
  

  

  