﻿168 
  

  

  THE 
  MOLLUSCA 
  OF 
  MAESASCIKOCCO 
  HARBOUR, 
  MALTA. 
  

  

  By 
  G. 
  Despott. 
  

  

  Bead 
  13th 
  June, 
  1919. 
  

  

  In 
  nearly 
  all 
  the 
  published 
  lists 
  of 
  the 
  Maltese 
  Marine 
  Mollusca 
  no 
  

   locality 
  is 
  given 
  for 
  the 
  majority 
  of 
  the 
  species 
  enumerated, 
  notwith- 
  

   standing 
  that 
  locality 
  is 
  one 
  of 
  the 
  most 
  impoitant 
  points 
  in 
  

   a 
  faunistic 
  list. 
  

  

  McAndrew 
  published 
  two 
  lists 
  of 
  species 
  obtained 
  by 
  him 
  in 
  these 
  

   waters 
  in 
  the 
  Report 
  of 
  the 
  British 
  Association 
  for 
  1850. 
  For 
  the 
  

   species 
  enumerated 
  in 
  the 
  first 
  list, 
  with 
  the 
  quantity 
  of 
  the 
  

   specimens 
  obtained, 
  he 
  gives 
  as 
  a 
  locality 
  " 
  A 
  ground 
  of 
  sand 
  and 
  

   stones 
  at 
  a 
  depth 
  of 
  -40 
  fathoms 
  1 
  to 
  2 
  miles 
  distant 
  from 
  the 
  shore". 
  

   For 
  the 
  species 
  on 
  the 
  second 
  list, 
  the 
  locality 
  given 
  is 
  simply 
  

   "a 
  sandy 
  bottom 
  6 
  to 
  12 
  and 
  15 
  fathoms 
  deep 
  in 
  the 
  harbour 
  of 
  

   INIalta 
  ", 
  while 
  the 
  frequency 
  of 
  occurrence 
  is 
  given 
  for 
  only 
  two 
  or 
  

   three 
  of 
  the 
  species 
  recorded. 
  

  

  In 
  Mamo's 
  list, 
  compiled 
  by 
  the 
  late 
  Dr. 
  A. 
  A. 
  Caruana, 
  the 
  

   locality 
  is 
  given 
  in 
  only 
  a 
  few 
  cases. 
  Such 
  localities, 
  however, 
  

   as 
  well 
  as 
  several 
  other 
  statements 
  made 
  in 
  this 
  list, 
  appear 
  now 
  to 
  

   be 
  somewhat 
  incorrect; 
  this, 
  nevertheless, 
  may 
  probably 
  be 
  due 
  to 
  

   the 
  great 
  change 
  which 
  has 
  taken 
  place 
  in 
  some 
  parts 
  of 
  our 
  harbours 
  

   since 
  Dr. 
  Caruana 
  published 
  his 
  list. 
  

  

  Similaj'ly, 
  the 
  locality 
  of 
  only 
  a 
  few 
  species 
  is 
  given 
  in 
  Benoit 
  and 
  

   Gulia's 
  list 
  published 
  in 
  II 
  Barth 
  of 
  1872, 
  and 
  the 
  frequency 
  of 
  

   occurrence 
  of 
  some 
  of 
  the 
  species 
  recorded 
  ha.«, 
  we 
  find, 
  varied 
  

   immensely. 
  

  

  Up 
  to 
  the 
  year 
  1912 
  I 
  entertained 
  doubts 
  about 
  many 
  of 
  the 
  

   statements 
  made 
  in 
  the 
  above-mentioned 
  publications, 
  and 
  in 
  many 
  

   cases 
  could 
  not 
  agree 
  with 
  mj' 
  friend 
  the 
  Contino 
  Dr. 
  A. 
  Caruana 
  

   Gatto, 
  who 
  is 
  undoubtedly 
  one 
  of 
  our 
  most 
  accurate 
  and 
  reliable 
  

   naturalists 
  (and 
  to 
  whom 
  I 
  am 
  much 
  indebted 
  for 
  help 
  in 
  malacology). 
  

   As 
  to 
  the 
  frequenc}^ 
  of 
  occurrence 
  of 
  several 
  species 
  of 
  mollusca 
  in 
  

   our 
  waters, 
  many 
  of 
  the 
  species 
  which 
  he 
  considered 
  common 
  were 
  

   according 
  to 
  my 
  experience 
  rare 
  ; 
  and, 
  on 
  the 
  other 
  hand, 
  I 
  had 
  

   collected 
  a 
  considerable 
  number 
  of 
  other 
  species 
  which 
  he 
  considered 
  

   rare. 
  Such 
  a 
  difference 
  of 
  opinion 
  was, 
  however, 
  mainly 
  due 
  to 
  the 
  

   fact 
  that 
  we 
  had 
  investigated 
  different 
  localities. 
  Till 
  that 
  time 
  

   I 
  had 
  limited 
  my 
  dredgings 
  to 
  the 
  harbour 
  of 
  Marsascirocco, 
  whence 
  

   since 
  1896 
  my 
  specimens 
  had 
  been 
  for 
  the 
  most 
  part 
  collected 
  ; 
  

   whilst 
  Dr. 
  Caruana 
  Gatto 
  and 
  the 
  late 
  Dr. 
  J. 
  S. 
  Galizia 
  had 
  carried 
  

   out 
  their 
  researches 
  in 
  tlie 
  Grand 
  and 
  Marsamuscetto 
  Harbours. 
  

  

  Such 
  a 
  marked 
  difference 
  having 
  then 
  been 
  observed 
  in 
  connection 
  

   with 
  the 
  frequency 
  of 
  occurrence 
  of 
  a 
  good 
  number 
  of 
  species, 
  which 
  

   difference 
  was 
  evidently 
  due 
  to 
  the 
  diversity 
  of 
  their 
  collection 
  

   in 
  either 
  time 
  or 
  locality, 
  or 
  probably 
  both, 
  and 
  knowing 
  moreover 
  

   that 
  the 
  various 
  works 
  which 
  are 
  being 
  continually 
  carried 
  out 
  in 
  

   several 
  harbours 
  must 
  necessarily 
  affect 
  some 
  of 
  the 
  species 
  

  

  