﻿130 
  PROCEEDINGS 
  OF 
  THE 
  MALACOLOQICAL 
  SOCIETY. 
  

  

  altliongh 
  eacli 
  contains 
  a 
  large 
  papilla, 
  as 
  in 
  H. 
  limhata 
  (Drap.). 
  

   Thus, 
  wliile 
  in 
  the 
  form 
  of 
  its 
  shell, 
  and 
  perhaps 
  also 
  in 
  its 
  jaw, 
  

   II. 
  cincteUd 
  {Braj).) 
  may 
  be 
  slightly 
  more 
  specialized 
  than 
  H. 
  limhata 
  

   (Drap.), 
  in 
  its 
  radula 
  and 
  reproductive 
  system 
  it 
  appears 
  to 
  be 
  a 
  little 
  

   more 
  primitive 
  than 
  its 
  ally. 
  

  

  The 
  probable 
  affinities 
  of 
  these 
  species 
  with 
  the 
  other 
  sections 
  of 
  

   Ilygromia 
  that 
  are 
  indigenous 
  to 
  the 
  British 
  Isles 
  and 
  France 
  will 
  

   be 
  most 
  clearly 
  seen 
  from 
  the 
  following 
  classification 
  : 
  — 
  

  

  « 
  

   Sub-genus 
  Hygromia, 
  PJsso, 
  s.s. 
  

  

  Shell 
  covered 
  with 
  extremely 
  fine 
  microscopical 
  ridges. 
  Marginal 
  

   teeth 
  with 
  bifid 
  mesocones. 
  Spermatheca 
  elongated. 
  A 
  single 
  

   dart-sac 
  and 
  accessory 
  sac. 
  

  

  Section 
  1.' 
  

  

  Shell 
  very 
  thin 
  and 
  somewhat 
  degenerate. 
  Dart 
  with 
  four 
  blades, 
  

   riagellum 
  long 
  ; 
  epiphallus 
  normal. 
  

   H. 
  fiisca 
  (Mont.). 
  

  

  Section 
  2. 
  

  

  Shell 
  frequently 
  with 
  an 
  opaque 
  white 
  peripheral 
  band. 
  Dait 
  

   (of 
  II. 
  limhata) 
  without 
  blades. 
  Flagellum 
  very 
  small 
  ; 
  epipliallus 
  

   extremely 
  long, 
  its 
  anterior 
  part 
  united 
  to 
  the 
  genital 
  atrium 
  by 
  

   retractor 
  muscles. 
  

  

  H. 
  cinctella 
  (Drap.). 
  

  

  H. 
  limhata 
  (Drap.). 
  

  

  Sub-genus 
  Monacha, 
  Fitz. 
  

  

  Shell 
  microscopically 
  granulate, 
  the 
  little 
  ridges 
  being 
  larger 
  than 
  

   in 
  tlie 
  last 
  sub-genus. 
  Mesocones 
  of 
  marginal 
  teeth 
  not 
  bifid. 
  

   Spermatheca 
  globular. 
  A 
  single 
  dart-sac. 
  

  

  77. 
  incarnafa 
  (Miill.). 
  

  

  77". 
  (jlahella 
  (Drap.). 
  

  

  Sub-genus 
  Tricuia, 
  Hartm.- 
  

  

  Shell 
  hispid 
  (at 
  least 
  when 
  young), 
  not 
  granulate. 
  Mesocones 
  of 
  

   marginal 
  teeth 
  not 
  bifid. 
  Spermatheca 
  globular. 
  Dart-sacs 
  and 
  

   accessory 
  sacs 
  paired. 
  

  

  ' 
  The 
  name 
  Zenobia, 
  Gray, 
  has 
  sometimes 
  been 
  used 
  for 
  this 
  section, 
  but 
  

   Pilsbry 
  has 
  shown 
  that 
  it 
  is 
  preoccupied 
  (Man. 
  Conch., 
  vol. 
  ix, 
  1894, 
  

   pp. 
  264-5). 
  

  

  - 
  Pilsbry 
  has 
  discarded 
  this 
  very 
  appropriate 
  name 
  in 
  favour 
  of 
  Fruticicola, 
  

   Held 
  (restricted), 
  on 
  the 
  grounds 
  that 
  the 
  name 
  Trichia 
  was 
  almost 
  certainly 
  

   preoccupied 
  by 
  deHaan, 
  and 
  that 
  Fruticicola 
  was 
  earlier, 
  dating 
  from 
  1837. 
  

   But 
  the 
  first 
  two 
  species 
  that 
  Held 
  gives 
  under 
  Fruticicola 
  are 
  II. 
  cinctella 
  

   and 
  H. 
  limhata, 
  and 
  it 
  might, 
  therefore, 
  seem 
  better 
  to 
  regard 
  Fruticicola 
  

   as 
  a 
  synonym 
  of 
  Ilygromia, 
  Eisso 
  (1826). 
  Moreover, 
  Trichia, 
  Hartm., 
  

   was 
  published 
  in 
  1840 
  (Erd- 
  unci 
  Silssivasser-Moll. 
  Sclitveiz, 
  p. 
  41) 
  ; 
  

   while 
  Trichia, 
  de 
  Haan, 
  appears 
  on 
  a 
  page 
  of 
  the 
  Fauna 
  Japonica 
  

   (vol. 
  V, 
  Crustacea), 
  which 
  is 
  dated 
  1841. 
  

  

  