﻿f 
  ) 
  Genus 
  Amaea 
  

  

  H. 
  & 
  

   Tone 
  

  

  A. 
  

  

  49 
  

   Opalia 
  discobolaria 
  Pall 
  (Gr. 
  discoboloSjj 
  

  

  a 
  thrower 
  of 
  the 
  discus; 
  the 
  "base 
  is 
  ; 
  

  

  disk-like.) 
  j 
  

  

  Opalia 
  pumilio 
  Mbrch 
  ( 
  dwarf 
  ; 
  length 
  10 
  mm.) 
  

   Opalia 
  pumilio 
  morchiana 
  Pall 
  (named 
  f 
  or 
  j 
  

  

  Otto 
  Andreas 
  L. 
  Morch, 
  1828-1878.) 
  j 
  

   Opalia 
  aurifila 
  Pal 
  l 
  (Lat. 
  auruiji, 
  gold 
  -i-[ 
  

  

  filutn, 
  thread; 
  fine 
  reticulated 
  pattern^ 
  

  

  color 
  light 
  and 
  dull 
  brown. 
  ) 
  i 
  

  

  Opalia 
  eolis 
  Cl 
  e 
  nch 
  & 
  Turner 
  (named 
  for 
  { 
  

  

  John 
  B. 
  Henderson's 
  yacht, 
  the 
  Eolis.) 
  j 
  

  

  Amaea 
  mitchelli 
  Pall 
  ( 
  Mi 
  t 
  che 
  1 
  1 
  ' 
  s 
  , 
  ) 
  

   Amaea 
  retifera 
  Pal 
  l 
  (having 
  a 
  net; 
  the 
  

   whorls 
  are 
  closely 
  reticulated; 
  they 
  ha 
  

   ve 
  quite 
  a 
  regular 
  reticulated 
  pattern.) 
  

  

  g 
  ) 
  G 
  enus 
  ITystiella 
  

  

  Clench 
  & 
  Turner 
  1953 
  , 
  

   (Pedicated 
  to 
  Pierre, 
  

   Henri 
  ITyst, 
  a 
  dis- 
  

   tinguished 
  Belgian 
  

   malacologist, 
  1815- 
  

   1880. 
  Fem. 
  ) 
  

  

  Adams 
  1854rT0ne 
  of 
  

   those 
  names 
  inven- 
  

   ted 
  by 
  the 
  brothers 
  

   Adams. 
  May 
  be 
  deri- 
  

   ved 
  from 
  Gr. 
  "a", 
  

   without 
  -I- 
  Lat.raaea, 
  

   a 
  crab; 
  without 
  a 
  

   crab 
  ( 
  inside 
  the 
  

   shell). 
  Fern.) 
  ■. 
  

  

  l^Tystiella 
  a 
  t 
  lantis 
  Clench 
  & 
  Turner 
  ( 
  named 
  

   after 
  the 
  ketch 
  Atlantis, 
  the 
  research 
  

   vessel 
  of 
  the 
  i7oods 
  Hole 
  Oceanographic 
  

   Institute 
  . 
  ) 
  

   Nystiel 
  la 
  azelotes 
  Pall 
  (Gr, 
  not 
  to 
  be 
  

  

  envied. 
  y~ 
  

   Nystiella 
  caniixm 
  Pall 
  (a 
  Gr, 
  noun, 
  caneon 
  

   or 
  caneion, 
  meaning 
  a 
  basket 
  of 
  reed 
  or 
  

   cane; 
  the 
  shell 
  is 
  reticulated.) 
  

   Nystiella 
  concava 
  Pall 
  (concave; 
  v/horls 
  

   quite 
  flattened; 
  base 
  quite 
  concave 
  

   from 
  the 
  carina 
  to 
  the 
  pillar 
  (in 
  the 
  

   type 
  , 
  ) 
  

  

  ! 
  Nystiella 
  opalina 
  P 
  all 
  ("the 
  flattish 
  

   j 
  whorls 
  and 
  shallow 
  suture 
  recall 
  Opalia', 
  

   ' 
  writes 
  Pall. 
  Shell 
  translucent 
  white.) 
  

   i 
  Epitonium 
  lavaratum 
  Pal 
  l 
  is 
  the 
  same. 
  

  

  V. 
  SUP 
  E 
  RFAMILY 
  H 
  I 
  PPONICACE 
  A 
  

  

  (Gr. 
  hippos, 
  horse 
  — 
  onyx, 
  a 
  hoof. 
  According 
  to 
  etymology, 
  Hipponica-' 
  

   cea, 
  Hipponicidae 
  and 
  Hipponix 
  should 
  be 
  written 
  Hipponj^cacea, 
  Hippo- 
  

   n^cidae 
  and 
  Hipponjrx. 
  Pall 
  writes: 
  "The 
  name 
  Hipponi^x 
  was 
  consistently 
  

   used 
  by 
  Pefrance 
  and 
  others, 
  and 
  no 
  derivation 
  given 
  in 
  the 
  original 
  

   diagnosis." 
  Common 
  name: 
  Hoof 
  Shells.) 
  

  

  1. 
  Family 
  Hipponicidae 
  . 
  (Same 
  etymology 
  as 
  above.) 
  

  

  a 
  ) 
  Genus 
  Cheilea 
  Modeer 
  

   1795. 
  (Gr. 
  cheilos, 
  

   lip; 
  the 
  shell 
  has 
  a 
  

   puckered 
  edge. 
  Fem, 
  ) 
  

  

  j 
  Cheilea 
  equestr 
  i 
  s 
  Linn 
  e 
  ( 
  equestrian;hor- 
  

   : 
  se-shoe 
  shaped 
  plate 
  inside 
  the 
  shell.) 
  

  

  i 
  Cheilea 
  equestris 
  t 
  ortilis 
  Reeve 
  ( 
  twisted 
  : 
  

   ! 
  crumpled 
  or 
  shrivelled 
  towards 
  margin.) 
  

  

  i 
  Hip 
  p 
  onix 
  antiquatus 
  Linn 
  e 
  ( 
  gr 
  ov/n 
  o 
  1 
  d 
  ; 
  the 
  

   I 
  periostracum 
  is 
  absent 
  or 
  very 
  thin.) 
  

  

  ; 
  Hipconix 
  b 
  enthophilus 
  Pall 
  (Gr. 
  benthos. 
  

  

  