﻿MELVILL 
  : 
  TUERIDiE 
  OF 
  THE 
  PERSIAN 
  GULF, 
  ETC. 
  171 
  

  

  commonest 
  form 
  in 
  the 
  Persian 
  Gulf 
  area, 
  and 
  its 
  variety 
  is 
  great, 
  

   both 
  elongate 
  and 
  abbreviate 
  forms 
  occurring 
  ; 
  others 
  (as 
  in 
  the 
  

   original 
  type 
  figured 
  from 
  the 
  National 
  Collection, 
  which 
  is 
  that 
  

   dredged 
  by 
  Sir 
  Lewis 
  Pelly 
  in 
  the 
  Persian 
  Gulf) 
  have 
  a 
  wider 
  mouth 
  

   and 
  sinus 
  and 
  shorter 
  canal. 
  

  

  I 
  suspect, 
  too, 
  that 
  the 
  shell 
  described 
  by 
  me 
  in 
  1903 
  as 
  Cythara 
  

   «lega7itiisima 
  is 
  but 
  another 
  variety, 
  and 
  as 
  such 
  merge 
  it 
  provisionally. 
  

  

  M. 
  gracilenta 
  is 
  placed 
  in 
  Clathurella 
  by 
  Hidalgo, 
  in 
  Mangilia 
  by 
  

   Hedley, 
  in 
  Drillia 
  by 
  Paetel. 
  The 
  peculiar 
  swollen 
  and 
  cancellate 
  

   third 
  whorl 
  are 
  most 
  distinctive, 
  and 
  when 
  the 
  time 
  comes 
  for 
  the 
  

   subdivision 
  of 
  these 
  now 
  much 
  confused 
  genera, 
  I 
  expect 
  specific 
  

   rank 
  will 
  be 
  granted 
  to 
  the 
  group 
  ranged 
  round 
  this 
  well-marked 
  and 
  

   widely 
  distributed 
  species, 
  which 
  is 
  now 
  only 
  beginning 
  to 
  be 
  under- 
  

   stood, 
  and 
  to 
  which 
  will 
  be 
  relegated 
  several 
  other 
  near 
  allies, 
  and 
  

   consequentlj' 
  its 
  synonymy 
  will 
  be 
  extensive. 
  

  

  88. 
  Mangilia 
  horneana 
  (Sm.). 
  (PL 
  IX, 
  Fig. 
  15.) 
  

   Pleurotorna 
  {^Clathurella) 
  horneana, 
  E. 
  A. 
  Smith, 
  Ann. 
  Mag. 
  Nat. 
  

  

  Hist., 
  ser. 
  v, 
  vol. 
  xiv, 
  1884, 
  p. 
  323. 
  

  

  P.G. 
  Bushire. 
  

  

  I. 
  Karachi. 
  Amongst 
  weed 
  and 
  rocks 
  at 
  low 
  tide, 
  locally 
  most 
  

   abundant, 
  and 
  probably 
  extending 
  much 
  further 
  south, 
  to 
  Ceylon 
  

   and 
  Madras. 
  

  

  The 
  type 
  is 
  a 
  gradate 
  shell. 
  The 
  variety, 
  witli 
  one 
  or 
  two 
  more 
  

   additional 
  longitudinal 
  costae 
  on 
  each 
  whorl, 
  and 
  closer, 
  finer 
  

   striation, 
  may 
  be 
  thus 
  characterized 
  : 
  — 
  

  

  Var. 
  eompar, 
  nov. 
  (PL 
  X, 
  Fig. 
  15.) 
  

  

  Testa 
  ut 
  in 
  typo, 
  sed 
  nequaquara 
  gradata, 
  costis 
  ad 
  anfractus 
  

   supei'nis 
  magis 
  numerosis, 
  simul 
  ac 
  liris 
  spiralibus 
  tenuissimis, 
  labro 
  

   extus 
  planato. 
  

  

  P.G. 
  M.C. 
  Fairly 
  distributed. 
  

  

  Long. 
  8, 
  lat. 
  3^ 
  mm. 
  

  

  This, 
  smoother 
  variety 
  is 
  more 
  abundant 
  than 
  the 
  type, 
  as 
  will 
  be 
  

   seen 
  on 
  reference 
  to 
  the 
  original 
  description, 
  and 
  we 
  think 
  it 
  is 
  

   a 
  pity 
  it 
  was 
  not 
  taken 
  as 
  the 
  leading 
  exponent 
  of 
  the 
  species. 
  It 
  is 
  

   also 
  larger 
  than 
  the 
  type, 
  now 
  figured 
  from 
  the 
  collection 
  of 
  the 
  

   British 
  Museum. 
  

  

  89. 
  Mangilia 
  heptaoona 
  (Dkr.). 
  (PL 
  IX, 
  Fig. 
  14.) 
  

   Clathurella 
  heptagona, 
  Dunker, 
  Malak. 
  Bliitt., 
  xviii, 
  1871, 
  p. 
  161. 
  

   I. 
  Bombay. 
  

  

  I 
  have 
  inspected 
  specimens 
  of 
  this 
  hitherto 
  unfigured 
  species 
  in 
  

   the 
  British 
  Museum, 
  I'eported 
  from 
  the 
  above 
  locality, 
  and 
  give 
  

   a 
  figure 
  of 
  it. 
  It 
  belongs 
  to 
  the 
  same 
  " 
  gens" 
  as 
  scitula, 
  Reeve, 
  and 
  

   I 
  should 
  not 
  deem 
  it 
  a 
  Clathurella. 
  

  

  90. 
  Mangilia 
  hexagonalis 
  (Reeve). 
  

   Pleurotorna 
  hexagonalis, 
  Reeve, 
  Proc. 
  Zool. 
  Soc. 
  Lond., 
  1845, 
  p. 
  118. 
  

   ,, 
  ,, 
  Reeve, 
  Conch. 
  Icon., 
  vol. 
  i, 
  1845, 
  pi. 
  xxxii, 
  

  

  f. 
  293. 
  

   P.G. 
  Gulf 
  of 
  Oman, 
  lat. 
  24° 
  58' 
  N., 
  long. 
  56° 
  54' 
  E., 
  156 
  fathoms. 
  

  

  VOL. 
  Xll. 
  — 
  APRIL, 
  1917. 
  13 
  

  

  