﻿246 
  PUOCHEDINGS 
  OF 
  THU 
  MALACOLOGICAL 
  SOCIETX". 
  

  

  number 
  of 
  four 
  as 
  a 
  rule. 
  Where 
  there 
  are 
  more 
  than 
  four 
  in 
  

   the 
  aperture, 
  the 
  extra 
  ones 
  appear 
  as 
  hardly 
  more 
  than 
  tubercles 
  or 
  

   continue 
  within 
  only 
  for 
  a 
  very 
  short 
  distance. 
  The 
  onlj' 
  species 
  

   that 
  I 
  have 
  examined 
  which 
  have 
  more 
  than 
  four 
  throughout 
  are 
  

   ventricosa, 
  Fischer, 
  and 
  its 
  very 
  near 
  relative 
  loelheckeana, 
  Wkff. 
  

   These 
  have 
  five. 
  Young 
  specimens 
  are 
  sometimes 
  found 
  to 
  have 
  

   a 
  larger 
  number 
  of 
  plaits 
  than 
  adults 
  of 
  the 
  same 
  species. 
  The 
  plaits 
  

   vary 
  in 
  the 
  angle 
  of 
  their 
  setting 
  on 
  the 
  columella, 
  and 
  it 
  is 
  obvious 
  

   that 
  in 
  the 
  Persicula 
  group, 
  which 
  has 
  no 
  spire, 
  they 
  will 
  be 
  practically 
  

   at 
  right 
  angles 
  to 
  the 
  axis. 
  

  

  One 
  very 
  curious 
  fact 
  about 
  this 
  family 
  which 
  has 
  often 
  been 
  

   commented 
  on 
  is 
  the 
  comparatively 
  large 
  number 
  of 
  cases 
  of 
  

   sinistrorsity 
  which 
  it 
  supplies. 
  This 
  teratological 
  feature 
  is 
  so 
  

   excessively 
  rare 
  amongst 
  recent 
  marine 
  Gastropods 
  that 
  I 
  know 
  of 
  

   only 
  thirty-seven 
  or 
  thirty-eight 
  species 
  in 
  which 
  it 
  is 
  on 
  record, 
  

   and 
  of 
  these 
  nineteen 
  or 
  50 
  per 
  cent 
  are 
  Marginellids. 
  Among 
  

   fossil 
  MoUusca 
  three 
  species 
  out 
  of 
  the 
  nine 
  so 
  recorded 
  belong 
  to 
  

   this 
  family. 
  

  

  The 
  Marginellidse 
  are 
  almost 
  exclusively 
  natives 
  of 
  warm 
  or 
  

   tropical 
  seas, 
  living 
  as 
  a 
  rule 
  on 
  sand 
  in 
  a 
  few 
  fathoms 
  of 
  water. 
  

   Occasionally 
  they 
  occur 
  between 
  tidemarks, 
  and 
  I 
  have 
  found 
  the 
  

   Mediterranean 
  M. 
  clandesiina, 
  Broc, 
  living 
  at 
  low 
  water 
  amongst 
  

   small 
  seaweeds 
  on 
  the 
  coast 
  of 
  Sicily. 
  Certain 
  species 
  have 
  been 
  

   dredged 
  at 
  considerable 
  depths 
  by 
  the 
  Challeuf/er, 
  Blake, 
  Travailleiir 
  & 
  

   Talisman, 
  etc. 
  With 
  very 
  few 
  exceptions 
  the 
  known 
  species 
  

   occur 
  between 
  the 
  40th 
  North 
  and 
  South 
  parallels 
  of 
  latitude, 
  and 
  

   though 
  they 
  are 
  of 
  general 
  occurrence 
  in 
  these 
  warmer 
  waters, 
  yet 
  

   certain 
  regions 
  are 
  noteworthy 
  as 
  producing 
  an 
  unusual 
  number 
  

   of 
  species, 
  namely, 
  the 
  West 
  African 
  coast, 
  the 
  Caribbean 
  region, 
  

   Australia, 
  and 
  the 
  Cape 
  district. 
  Curiously 
  enough, 
  the 
  first 
  three 
  of 
  

   these, 
  as 
  at 
  present 
  known, 
  have 
  each 
  about 
  seventy-four 
  or 
  seventy- 
  

   five 
  species. 
  Probably 
  Australia 
  will 
  add 
  to 
  this 
  total 
  in 
  the 
  future 
  

   much 
  more 
  largely 
  than 
  either 
  of 
  the 
  others. 
  On 
  the 
  West 
  African 
  

   coast 
  the 
  Marginellids 
  form 
  quite 
  an 
  appreciable 
  fraction 
  of 
  the 
  

   molluscan 
  fauna; 
  the 
  Gruvel 
  Expedition 
  in 
  1909-10 
  dredged 
  thirty- 
  

   four 
  out 
  of 
  a 
  total 
  of 
  519 
  species, 
  or 
  6 
  J 
  per 
  cent. 
  The 
  northern 
  and 
  

   southern 
  limits 
  of 
  the 
  west 
  coast 
  fauna 
  are 
  rather 
  sharply 
  defined, 
  

   tlie 
  former 
  being 
  somewhere 
  about 
  the 
  Tropic 
  of 
  Cancer, 
  the 
  latter 
  in 
  

   the 
  neighbourhood 
  of 
  Mossamedes. 
  A 
  small 
  parcel 
  recently 
  received 
  

   from 
  VValfisch 
  Bay 
  consists 
  entirely 
  of 
  a 
  species 
  either 
  identical 
  with, 
  

   or 
  at 
  most 
  a 
  variety 
  of 
  31. 
  capensis, 
  Krauss. 
  The 
  300 
  miles 
  of 
  coast 
  

   from 
  Mossamedes 
  to 
  Capetown 
  seems 
  singularly 
  little 
  known, 
  but 
  its 
  

   fauna 
  will, 
  I 
  think, 
  prove 
  to 
  belong 
  to 
  the 
  Cape. 
  Three 
  species 
  

   of 
  Marginella 
  are 
  known 
  from 
  St. 
  Helena, 
  one 
  from 
  Ascension, 
  and 
  

   forty-three 
  from 
  the 
  Cape. 
  Four 
  or 
  five 
  only 
  occur 
  on 
  the 
  East 
  

   African 
  coast, 
  while 
  the 
  Mascarenes 
  have 
  fourteen. 
  Fifty-six 
  species 
  

   are 
  scattered 
  from 
  the 
  Ued'Sea 
  eastwards 
  to 
  the 
  China 
  Sea, 
  and 
  

   seventeen 
  are 
  recorded 
  from 
  various 
  stations 
  in 
  the 
  Pacific. 
  As 
  

   already 
  stated, 
  Australian 
  waters 
  at 
  present 
  account 
  for 
  seventy-five, 
  

   and 
  New 
  Zealand 
  has 
  ten 
  endemic 
  species. 
  On 
  the 
  Pacific 
  coast 
  of 
  

  

  