﻿40 
  COLLECTTONS 
  FROM 
  MELANESIA. 
  

  

  transverse 
  lirje 
  are 
  nodose 
  on 
  crossing 
  the 
  ribs, 
  tliree 
  in 
  number 
  

   npon 
  the 
  upper 
  whorls, 
  a 
  fourth 
  being 
  present 
  upon 
  the 
  lower 
  part 
  

   of 
  the 
  penultimate 
  and 
  sixteen 
  to 
  eighteen 
  on 
  the 
  last. 
  Another 
  

   feature 
  worth 
  noticing 
  is 
  the 
  presence 
  of 
  a 
  finer 
  thread-like 
  line 
  

   above 
  the 
  uppermost 
  of 
  the 
  chief 
  lirse, 
  which 
  runs 
  in 
  a 
  slight 
  con- 
  

   cavity 
  at 
  the 
  upper 
  part 
  of 
  the 
  whorls. 
  

  

  The 
  aperture 
  is 
  narrow, 
  as 
  is 
  the 
  shell 
  itself, 
  not 
  greatly 
  contracted 
  

   at 
  the 
  canal, 
  and 
  occupies 
  rather 
  less 
  than 
  half 
  the 
  length 
  of 
  the 
  

   shell. 
  The 
  columella 
  is 
  subperpendicular, 
  a 
  little 
  tortuous 
  and 
  

   smooth, 
  without 
  lira; 
  or 
  tubercles. 
  The 
  outer 
  lip 
  is 
  thickened 
  with 
  

   an 
  exterior 
  rib, 
  but 
  thin 
  and 
  sharp 
  at 
  the 
  extreme 
  margin. 
  It 
  is 
  

   widely 
  and 
  semicircularly 
  notched 
  above 
  just 
  below 
  the 
  suture 
  in 
  

   the 
  faint 
  concavity 
  of 
  the 
  whorl, 
  and 
  generally 
  in 
  adult 
  shells 
  bears 
  

   a 
  small 
  tubercle 
  within 
  close 
  to 
  or 
  just 
  below 
  the 
  sinus, 
  with 
  which 
  

   exception 
  it 
  is 
  smooth. 
  

  

  8. 
  Pleurotoma 
  (Daphnella) 
  axis. 
  

  

  Plem'otoma 
  axis, 
  Reeve, 
  Conch. 
  Icon. 
  fig. 
  311. 
  

  

  Hah. 
  Port 
  Molle, 
  14 
  fms. 
  (Copjyinger) 
  ; 
  Philippines 
  (Cuming). 
  

  

  The 
  apical 
  whorls 
  of 
  this, 
  as 
  in 
  all 
  the 
  other 
  species 
  of 
  the 
  

   group 
  Daphnella, 
  are 
  microscopically 
  cancellated 
  by 
  oblique 
  criss- 
  

   cross 
  lines. 
  The 
  four 
  or 
  five 
  succeeding 
  volutions 
  are 
  coarsely 
  can- 
  

   cellated 
  by 
  longitudinal 
  costse 
  and 
  spiral 
  ridges, 
  the 
  points 
  of 
  inter- 
  

   section 
  being 
  subnodose. 
  Beyond 
  this 
  the 
  remaining 
  whorls 
  (about 
  

   three 
  in 
  number) 
  are 
  destitute 
  of 
  the 
  costse, 
  exhibiting 
  only 
  spiral 
  

   ridging 
  of 
  different 
  degrees 
  of 
  fineness 
  and 
  intermediate 
  finer 
  striae 
  

   crossed 
  only 
  by 
  the 
  lines 
  of 
  growth. 
  

  

  One 
  of 
  these 
  ridges 
  towards 
  the 
  upper 
  part 
  of 
  the 
  whorls 
  is 
  

   especially 
  prominent, 
  giving 
  them 
  a 
  somewhat 
  shouldered 
  appearauce, 
  

   and 
  between 
  this 
  and 
  the 
  upper 
  thicl-ened 
  margin 
  there 
  is 
  a 
  decided 
  

   concavity. 
  The 
  aperture 
  is 
  elongate, 
  contracted 
  anteriorly 
  into 
  a 
  

   distinct 
  and 
  somewhat 
  recurving 
  canal, 
  together 
  occupying 
  a 
  little 
  

   less 
  than 
  half 
  the 
  total 
  length 
  of 
  the 
  shell. 
  The 
  labrum 
  is 
  a 
  trifle 
  

   thickened, 
  presenting 
  exteriorly 
  a 
  slightly 
  swollen 
  appearance, 
  has 
  

   a 
  rather 
  deep 
  slit 
  above 
  at 
  the 
  suture, 
  is 
  smooth 
  within, 
  and 
  crenu- 
  

   lated 
  finely 
  along 
  the 
  edge. 
  

  

  9. 
  Pleurotoma 
  (Daphnella) 
  arafurensis. 
  (Plate 
  IV. 
  fig. 
  G.) 
  

  

  Shell 
  fusiform, 
  whitish, 
  faintly 
  banded 
  with 
  light 
  brown, 
  spirally 
  

   ridged 
  and 
  striated 
  and 
  marked 
  with 
  the 
  flcxuous 
  lines 
  of 
  growth. 
  

   Whorls 
  7 
  ; 
  two 
  apical 
  globose, 
  microscopically 
  reticulated, 
  but 
  ap- 
  

   pearing 
  smooth 
  under 
  an 
  ordinary 
  lens, 
  rather 
  large 
  ; 
  the 
  remain- 
  

   ing 
  five 
  are 
  convex, 
  a 
  little 
  constricted 
  beneath 
  the 
  suture, 
  and 
  

   spirally 
  ridged 
  and 
  striated. 
  The 
  upper 
  whorls 
  have 
  four 
  or 
  five 
  

   principal 
  linr, 
  the 
  uppermost 
  falling 
  just 
  beneath 
  the 
  slight 
  con- 
  

   striction, 
  and 
  the 
  others 
  below 
  at 
  equal 
  distances. 
  The 
  whorls 
  are 
  

   thickened 
  at 
  or 
  immediately 
  under 
  the 
  sut'jral 
  line 
  with 
  an 
  elevated 
  

  

  