﻿C. 
  ORDER 
  

  

  146 
  

   FILIBRANCHIA 
  

  

  (Lat. 
  filum, 
  threads 
  -•- 
  Gr. 
  branchia, 
  gills. 
  The 
  gill-filaments 
  are 
  j 
  

   ' 
  long, 
  folded 
  back 
  against 
  themselves 
  and 
  connected 
  "by 
  tiny 
  cilia.) 
  i 
  

  

  SUBORDER 
  T 
  A 
  XODONTA 
  

  

  I 
  (Gr. 
  taxis, 
  order, 
  arrangement 
  — 
  odous, 
  odont-, 
  tooth. 
  Hinge 
  teeth 
  of 
  

   ' 
  equal 
  size 
  and 
  arranged 
  in 
  a 
  long 
  series.) 
  

  

  I 
  

  

  SUPERFAIIILY 
  ARC 
  ACE 
  A 
  

  

  (Lat. 
  area, 
  a 
  chest, 
  an 
  ark. 
  Ark 
  Shells.) 
  

  

  1, 
  Eamily 
  Arcidae 
  . 
  (Same 
  etymology 
  as 
  above.) 
  

  

  a 
  ) 
  G 
  e 
  nu 
  s 
  Area 
  Linne 
  

  

  b) 
  Genus 
  

  

  Barb 
  atia 
  

   (Lat. 
  

  

  1847 
  . 
  (Lat. 
  barbatus 
  

   bearded. 
  Periostracumi 
  

   is 
  shaggy. 
  Eem. 
  ) 
  I 
  

  

  c 
  ) 
  Genus 
  Bathya 
  r 
  ca 
  Ko 
  - 
  

   belt 
  1891. 
  (Gr. 
  ba- 
  

   Lat 
  . 
  

  

  thys, 
  

   area, 
  

  

  deep 
  -:- 
  

  

  an 
  ark.Fem.) 
  

  

  1 
  Are 
  a 
  zebra 
  Swainson 
  (zebra; 
  formerly 
  listl- 
  

   i 
  ed 
  as 
  Area 
  occide 
  ntalis 
  Philippi 
  (west- 
  

   1758 
  J 
  ern; 
  belonging 
  to 
  the 
  "/estern 
  Hemisphere, 
  

   '[ 
  Area 
  umbonata 
  Lamarck 
  (Lat. 
  umbo, 
  umbonis 
  

   ! 
  a 
  protuberance, 
  rounded 
  elevation, 
  knob, 
  

   ' 
  Beaks 
  are 
  prominent. 
  Beaked 
  Ark.) 
  

  

  I 
  Barbatia 
  ca 
  nc 
  ellaria 
  Lamarck 
  ( 
  or 
  o 
  s 
  s-barreq: 
  

   ! 
  with 
  a 
  cancellate 
  sculpture; 
  formerly 
  

   j 
  known 
  as 
  Barba 
  t 
  ia 
  barbata 
  Linne 
  (bearded 
  

   ; 
  hairy; 
  the 
  periostracura 
  is 
  shaggy. 
  Bar- 
  

   ' 
  batia 
  barbata 
  Linne 
  is 
  a 
  Mediterranean 
  

   G 
  ray 
  ; 
  species. 
  ) 
  

  

  Barba 
  t 
  ia 
  Can 
  di 
  da 
  Helbling 
  (white; 
  white 
  

  

  inside 
  and 
  outside. 
  ) 
  

   j 
  Bar 
  b 
  atia 
  domingensis 
  Lamarck 
  (from 
  Santo 
  

   : 
  Domingo, 
  West 
  Indies; 
  formerly 
  called 
  

   '■ 
  Area 
  re 
  t 
  iculata 
  G 
  melin 
  (trellis-like; 
  

   ' 
  shell 
  has 
  radiating 
  ribs 
  crossed 
  by 
  con- 
  

   : 
  centric 
  ridges.) 
  

  

  i 
  Barbatia 
  teh 
  e 
  ra 
  C.B. 
  A 
  dams 
  (thin, 
  tender; 
  

   I 
  shell 
  is 
  thin. 
  Area 
  bal 
  es 
  i 
  Pil 
  sb 
  ry 
  and 
  

   i 
  McLean 
  (named 
  in 
  honor 
  of 
  Dr. 
  Blenn 
  R. 
  

   !_ 
  Bales, 
  1876-1946) 
  is 
  the 
  same 
  species.) 
  

  

  i 
  Bathyarca 
  anomala 
  Ve 
  r 
  rill 
  & 
  Bush 
  ( 
  abnor- 
  

   mal; 
  unusually 
  wide 
  ligamental 
  area.) 
  

  

  Bathyarca 
  abyssorum 
  Verr 
  ill 
  & 
  Bush 
  ( 
  of 
  

   the 
  abysses, 
  of 
  the 
  deep; 
  dredged 
  in 
  

   1825-1859 
  fathoms.) 
  

  

  Bathyarca 
  glaci 
  a 
  lis 
  Gray 
  ( 
  g 
  la 
  c 
  i 
  al 
  ; 
  f 
  ound 
  

  

  in 
  Gulf 
  of 
  St. 
  Lawrence.) 
  

  

  Bathy 
  a 
  rca 
  g 
  lomerula 
  Pall 
  (diminutive 
  of 
  

   glomus, 
  a 
  little 
  ball. 
  Shell 
  round.) 
  

  

  Bathyar 
  ca 
  i 
  naeg 
  ualis 
  Pal 
  l 
  (unequal; 
  shell 
  

   inequilateral, 
  anterior 
  end 
  short 
  and 
  

   attenuated, 
  posterior 
  end 
  longer 
  and 
  wi- 
  

   dely 
  expanded.) 
  

  

  Bathyar 
  ca 
  o 
  r 
  biculata 
  Pal 
  l 
  (rounded, 
  near- 
  

   ly 
  circular.) 
  j 
  

  

  Bathya 
  rca 
  pectunculoid 
  e 
  s 
  Scacchi 
  (Latin 
  ■. 
  

   pectunculus, 
  a 
  small 
  scallop 
  -'- 
  oides, 
  

   for 
  Gr. 
  eidos, 
  shape, 
  form; 
  resembling 
  ., 
  

  

  