﻿38 
  COLLECTIONS 
  FROM 
  MELANESIA. 
  

  

  This 
  is 
  a 
  more 
  robust 
  species 
  than 
  P. 
  varicosa 
  of 
  Reeve, 
  is 
  dif- 
  

   ferently 
  coloured, 
  has 
  more 
  prominent 
  spiral 
  ridges, 
  a 
  larger 
  number 
  

   of 
  costaj, 
  fewer 
  swollen 
  varices, 
  and 
  a 
  more 
  undulating 
  duplex 
  ridge 
  

   bordering 
  the 
  whorls 
  above. 
  These 
  two, 
  together 
  with 
  Drillia 
  

   tiiberosa, 
  Smith, 
  from 
  Japan, 
  form 
  a 
  small 
  group 
  of 
  species 
  peculiar 
  

   on 
  account 
  of 
  the 
  varicose 
  ribs 
  which 
  strengthen 
  the 
  shell 
  at 
  

   intervals. 
  * 
  

  

  5. 
  Pleurotoma 
  (Drillia) 
  laterculata. 
  (Plate 
  IV. 
  figs. 
  E-E 
  1.) 
  

   Pleurotoma 
  laterculata, 
  Sotverby, 
  Proc. 
  Zool. 
  Soc. 
  1870, 
  p. 
  253. 
  

  

  Hab. 
  China 
  Seas 
  (Soiverby) 
  ; 
  var. 
  Port 
  Molle, 
  Queensland, 
  

   12-20 
  fms., 
  rocky 
  bottom 
  {Goppinger). 
  

  

  As 
  the 
  description 
  given 
  by 
  Sowerby 
  is 
  altogether 
  inadequate, 
  I 
  

   herewith 
  append 
  a 
  more 
  detailed 
  one 
  drawn 
  up 
  from 
  the 
  type 
  

   specimen 
  presented 
  by 
  Mrs. 
  Lombc 
  Taylor 
  to 
  the 
  British 
  Museum. 
  

  

  Shell 
  fusiform, 
  whitish, 
  much 
  spotted 
  and 
  variegated 
  with 
  reddish 
  

   brown, 
  principally 
  between 
  the 
  longitudinal 
  ribs, 
  with 
  a 
  light 
  violet 
  

   aperture. 
  Whorls 
  probably 
  11 
  ; 
  two 
  apical 
  broken 
  away 
  ; 
  the 
  

   rest 
  verj;- 
  concave 
  above, 
  angulated 
  at 
  the 
  middle, 
  a 
  little 
  convex 
  

   beneath 
  and 
  contracted 
  towards 
  the 
  suture, 
  strengthened 
  with 
  

   rather 
  oblique 
  costse 
  (about 
  10 
  or 
  11 
  on 
  the 
  upper 
  whorls), 
  irre- 
  

   gularly 
  continuous 
  up 
  the 
  spire, 
  somewhat 
  obsolete 
  in 
  the 
  concavity 
  

   of 
  the 
  whorls, 
  which 
  are 
  also 
  ornamented 
  with 
  two 
  thread-like 
  

   pale 
  lirae 
  round 
  the 
  middle 
  forming 
  a 
  kind 
  of 
  double 
  angle, 
  con- 
  

   tinuous 
  between 
  and 
  upon 
  the 
  costce, 
  where 
  they 
  become 
  subacutely 
  

   prominent 
  ; 
  beneath 
  these, 
  in 
  the 
  penultimate 
  and 
  the 
  antepenulti- 
  

   mate 
  volutions, 
  there 
  is 
  a 
  third 
  near 
  the 
  suture. 
  Last 
  whorl 
  en- 
  

   circled 
  with 
  a]iout 
  thirteen 
  similar 
  pale 
  liroe, 
  besides 
  intcrlying 
  finer 
  

   ones, 
  and 
  several 
  at 
  the 
  extremity 
  which 
  are 
  very 
  oblique. 
  Canal 
  

   straight, 
  feebly 
  recurved, 
  together 
  with 
  the 
  aperture 
  equalling 
  less 
  

   than 
  half 
  the 
  whole 
  length 
  of 
  the 
  shell. 
  Columella 
  perpendicular, 
  

   covered 
  with 
  a 
  thin 
  callosity, 
  developed 
  into 
  a 
  tubercle 
  close 
  to 
  the 
  

   upper 
  extremity 
  of 
  the 
  outer 
  lip. 
  The 
  latter 
  is 
  thin 
  at 
  the 
  margin, 
  

   has 
  a 
  strong 
  swollen 
  varix 
  behind, 
  arcuately 
  prominent 
  at 
  the 
  

   middle, 
  with 
  a 
  well-marked 
  sinus 
  above 
  in 
  the 
  concavity. 
  Length 
  

   80 
  millim., 
  width 
  10 
  ; 
  aperture 
  with 
  canal 
  14 
  long. 
  

  

  Variety. 
  Shell 
  of 
  similar 
  form 
  and 
  with 
  the 
  same 
  sculpture, 
  but 
  

   much 
  less 
  highly 
  variegated. 
  Of 
  a 
  dirty 
  white 
  colour, 
  stained 
  in 
  

   the 
  concavity 
  of 
  the 
  whorls 
  at 
  the 
  lower 
  part 
  next 
  the 
  suture 
  and 
  

   round 
  the 
  middle 
  of 
  the 
  last 
  between 
  the 
  ribs 
  with 
  pale 
  olive-brown. 
  

   Extremity 
  of 
  the 
  body-whorl 
  and 
  the 
  swollen 
  varix 
  suff'used 
  with 
  a 
  

   reddish 
  tint. 
  Aperture 
  pale 
  lilac 
  or 
  whitish. 
  The 
  entire 
  surface 
  

   of 
  this 
  species 
  is 
  seen, 
  by 
  the 
  aid 
  of 
  a 
  lens, 
  to 
  be 
  striated 
  with 
  

   minute 
  spiral 
  stri?e, 
  crossed 
  by 
  lines 
  of 
  growth. 
  The 
  most 
  striking 
  

   feature 
  is 
  the 
  two 
  white 
  fine 
  lirations 
  at 
  the 
  middle 
  of 
  the 
  whorls 
  : 
  

   and 
  although 
  at 
  times 
  there 
  may 
  be 
  one 
  or 
  two 
  beneath 
  them, 
  none 
  

   appear 
  to 
  be 
  found 
  in 
  the 
  concavity 
  above. 
  The 
  two 
  apical 
  whorls 
  

   are 
  smooth, 
  glossy, 
  and 
  convex. 
  

  

  