﻿88 
  PROCEEDINGS 
  OF 
  THE 
  MALACOLOGICAL 
  SOCIETY. 
  

  

  The 
  presence 
  of 
  certain. 
  of 
  tlie 
  Cypridse 
  in 
  the 
  water 
  seems 
  fatal 
  

   to 
  the 
  snails 
  : 
  this 
  is 
  a 
  carefully 
  ascertained 
  fact, 
  confirmed 
  by 
  very 
  

   many 
  experiments, 
  and 
  quite 
  beyond 
  doubt, 
  Cypris 
  is 
  almost 
  

   ubiquitous 
  — 
  it 
  makes 
  its 
  apj)earance 
  even 
  when 
  the 
  utmost 
  care 
  is 
  

   taken 
  to 
  guard 
  against 
  it. 
  There 
  are 
  numerous 
  species, 
  and 
  I 
  am 
  

   not 
  prepared 
  to 
  admit 
  that 
  all 
  are 
  sinners, 
  but 
  in 
  any 
  case 
  tlie 
  enemy 
  

   is 
  one 
  of 
  the 
  smaller 
  forms 
  that 
  is 
  nearly 
  always 
  present 
  : 
  the 
  

   larger 
  kinds 
  seem 
  to 
  be 
  ignored 
  by 
  the 
  snails. 
  It 
  is 
  still 
  a 
  matter 
  of 
  

   doubt 
  as 
  to 
  what 
  takes 
  place. 
  From 
  observations 
  repeatedly 
  made 
  

   I 
  find 
  the 
  snails 
  usually 
  imprison 
  any 
  foreign 
  body 
  which 
  gains 
  

   access 
  into 
  their 
  shells, 
  and 
  perish 
  whilst 
  waiting 
  for 
  the 
  discomfort 
  

   thereby 
  caused 
  to 
  pass 
  away. 
  Possibly 
  something 
  like 
  this 
  happens 
  

   in 
  the 
  case 
  of 
  Cypris 
  finding 
  an 
  entrance. 
  The 
  larger 
  kinds 
  of 
  

   snails 
  are 
  the 
  chief 
  victims 
  : 
  P. 
  vortex, 
  to 
  some 
  extent, 
  but 
  the 
  

   smaller 
  snails 
  are 
  able 
  to 
  escape 
  the 
  attentions 
  of 
  Cypris 
  — 
  possibly 
  

   being 
  so 
  small 
  there 
  is 
  little 
  room 
  for 
  an 
  entrance. 
  

  

  ON 
  THE 
  FIKST 
  DISCOVEEY 
  IN 
  ENGLAND 
  OF 
  HELICODONTA 
  

  

  OBVOLUTA 
  (MULL.). 
  

  

  By 
  A. 
  S. 
  Kennaud, 
  F.G.S., 
  and 
  B. 
  B. 
  Woodward, 
  F.L.S. 
  

  

  Bead 
  lOtli 
  January, 
  1919. 
  

  

  It 
  is 
  generally 
  stated 
  that 
  Helicodonta 
  ohvoluta 
  was 
  first 
  noticed 
  in 
  

   England 
  in 
  1830 
  by 
  Dr. 
  J. 
  Lindsay, 
  but 
  we 
  would 
  call 
  attention 
  to 
  

   a 
  possible 
  earlier 
  record. 
  This 
  occurs 
  in 
  a 
  now 
  forgotten 
  work 
  on 
  

   Natural 
  History 
  bj' 
  Dr. 
  R. 
  Brookes. 
  The 
  fourth 
  volume 
  is 
  entitled 
  

   The 
  Natural 
  Uistory 
  of 
  Insects, 
  toith 
  their 
  Properties 
  and 
  Uses 
  in 
  

   Iledicine, 
  and 
  was 
  published 
  in 
  London 
  in 
  1768. 
  

  

  In 
  it 
  occurs, 
  on 
  pp. 
  302-3, 
  the 
  following 
  entry: 
  "The 
  tvhitish 
  

   depressed 
  snail 
  tvith 
  a 
  dentated 
  mouth 
  is 
  about 
  half 
  an 
  inch 
  broad 
  and 
  

   its 
  height 
  no 
  more 
  than 
  the 
  third 
  of 
  an 
  inch. 
  It 
  consists 
  of 
  three 
  or 
  

   four 
  spiral 
  turns 
  and 
  has 
  a 
  flat 
  clavicle 
  [= 
  spire]. 
  The 
  mouth 
  is 
  

   about 
  a 
  quarter 
  of 
  an 
  inch 
  long 
  and 
  almost 
  as 
  much 
  broad, 
  which 
  

   makes 
  the 
  figure 
  nearly 
  roundish. 
  It 
  has 
  a 
  pretty 
  broad 
  lip 
  of 
  a 
  

   pearly 
  white, 
  and 
  is 
  slightly 
  dentated 
  on 
  each 
  side. 
  The 
  colour 
  of 
  

   the 
  whole 
  shell 
  is 
  whitish 
  without 
  any 
  variegation. 
  It 
  is 
  said 
  to 
  be 
  

   met 
  with 
  in 
  Charlton 
  forest, 
  in 
  Sussex, 
  and 
  is 
  pretty 
  common 
  in 
  

   Italy." 
  Charlton 
  is 
  situate 
  5v 
  miles 
  south 
  of 
  Midhurst 
  and 
  on 
  the 
  

   South 
  Downs: 
  it 
  is 
  thus 
  in 
  the 
  ^'■ohvoluta 
  country". 
  It 
  would 
  

   therefore 
  appear 
  that 
  dead 
  examples 
  of 
  II. 
  ohvoluta 
  luid 
  been 
  found 
  

   in 
  Sussex 
  by 
  some 
  earl 
  3' 
  collector 
  prior 
  to 
  1768. 
  

  

  