﻿362 
  COLLECTIONS 
  FROM 
  MELANESIA. 
  

  

  lemon-yellow. 
  The 
  species 
  has 
  to 
  be 
  referred 
  to 
  Acaharia, 
  as 
  it 
  

   wants 
  the 
  foliated 
  spicules 
  (Blattkeulen) 
  characteristic 
  of 
  Mopsella. 
  

  

  Hab. 
  Port 
  Darwin, 
  Australia, 
  8-15 
  fms. 
  ; 
  bottom 
  mud. 
  

  

  Ohs. 
  The 
  distribution 
  of 
  this 
  specie^, 
  hitherto 
  known 
  only 
  from 
  

   Japan, 
  is 
  not 
  by 
  any 
  means 
  unparalleled 
  (cf. 
  Echinomuricea 
  inclo- 
  

   malaccensis, 
  p. 
  336, 
  extending 
  from 
  China 
  to 
  jST.E. 
  Australia) 
  ; 
  the 
  

   species 
  has 
  not 
  hitherto 
  been 
  recorded 
  from 
  anj^ 
  point 
  between 
  

   Australia 
  and 
  Japan. 
  

  

  Dana's 
  species 
  (v. 
  supra), 
  from 
  the 
  Sandwich 
  Islands, 
  is 
  probably 
  

   nearly 
  allied 
  if 
  not 
  identical 
  with 
  this, 
  but 
  the 
  original 
  description 
  is 
  

   insufficient 
  to 
  decide 
  the 
  point. 
  

  

  36. 
  Acabaria 
  serrata. 
  

   (Plate 
  XXXVII. 
  figs. 
  E, 
  E' 
  ; 
  Plate 
  XXXVIII. 
  figs, 
  c-c".) 
  

  

  Corallum 
  erect, 
  branching 
  dichotomously 
  at 
  angles 
  of 
  30° 
  to 
  40°, 
  

   strictly 
  in 
  one 
  plane 
  ; 
  anastomosis 
  absent 
  or 
  rare. 
  Base 
  ? 
  Main 
  stem 
  

   slender, 
  not 
  exceeding 
  2-5 
  millim. 
  in 
  diameter. 
  Internodes 
  slender, 
  

   slightly 
  flexuous, 
  8-10 
  millim. 
  long 
  as 
  a 
  rule, 
  compressed 
  from 
  

   front 
  to 
  back, 
  decreasing 
  slightly 
  in 
  diameter 
  towards 
  periphery, 
  

   viz. 
  from 
  about 
  1-5 
  millim. 
  lateral 
  diameter 
  near 
  base 
  to 
  -75 
  millim. 
  

   at 
  tips 
  of 
  branches 
  (exclusive 
  of 
  tubercles) 
  ; 
  antero-posterior 
  diameter 
  

   only 
  about 
  half 
  as 
  great 
  as 
  the 
  lateral 
  diameter. 
  Internodes 
  

   compact, 
  apparently 
  imperforate 
  throughout 
  ; 
  axis 
  deep 
  crimson- 
  

   red. 
  Soft 
  joints 
  distinct, 
  spherical, 
  nearly 
  twice 
  the 
  diameter 
  

   (taken 
  laterally) 
  of 
  the 
  adjacent 
  internodes, 
  except 
  near 
  periphery, 
  

   where 
  they 
  are 
  no 
  thicker 
  than 
  the 
  internodes 
  ; 
  substance 
  compact, 
  

   deep 
  crimson. 
  

  

  Cortex 
  very 
  thin, 
  but 
  compact, 
  smooth, 
  deep 
  crimson 
  (in 
  spirit) 
  in 
  

   adult, 
  white 
  to 
  pale 
  scarlet 
  in 
  young 
  specimens. 
  Verrucse 
  usually 
  

   forming 
  a 
  strictly 
  single 
  row 
  down 
  each 
  lateral 
  margin 
  of 
  the 
  

   branches 
  ; 
  in 
  closed 
  state 
  rounded 
  and 
  but 
  slightly 
  prominent 
  ; 
  in 
  

   open 
  state 
  truncate-conical, 
  about 
  "5 
  millim. 
  in 
  height, 
  serrating 
  the 
  

   edges 
  of 
  the 
  branches 
  in 
  a 
  manner 
  peculiar 
  to 
  this 
  species 
  in 
  its 
  genus 
  ; 
  

   their 
  bases 
  are 
  just 
  free 
  from 
  each 
  other; 
  colour 
  (in 
  spirit) 
  pale 
  yellow. 
  

   Spicules 
  of 
  cortex 
  : 
  — 
  (i.) 
  Fusiform 
  or 
  subclavate, 
  curved, 
  tuberculato, 
  

   one 
  end 
  usually 
  well 
  pointed, 
  the 
  other 
  more 
  or 
  less 
  obscured 
  at 
  one 
  

   side 
  by 
  projection 
  of 
  large 
  tubercles 
  ; 
  tubercles 
  distinct 
  from 
  each 
  

   other, 
  but 
  not 
  arranged 
  in 
  whorls, 
  long, 
  pointed, 
  rather 
  ragged 
  ; 
  

   those 
  of 
  the 
  convex 
  side 
  very 
  prominent 
  towards 
  the 
  larger 
  end 
  

   and 
  inclined 
  towards 
  this 
  end 
  ; 
  size 
  -21 
  by 
  -062 
  millim. 
  (ii.) 
  Smaller, 
  

   shorter, 
  blunt 
  or 
  almost 
  so, 
  with 
  thick 
  shaft 
  and 
  two 
  median 
  whorls 
  

   of 
  tubercles, 
  low, 
  rough, 
  transversely 
  elongated, 
  forming 
  almost 
  

   continuous 
  ridges 
  round 
  the 
  spicule, 
  and 
  a 
  whorl 
  of 
  incipient 
  tuber- 
  

   cles 
  surrounding 
  each 
  blunt 
  end 
  ; 
  size 
  '088 
  to 
  '12 
  by 
  -053 
  millim. 
  

   Spicules 
  of 
  verrucae 
  : 
  — 
  (iii-) 
  Horizontal, 
  fusiform, 
  curved, 
  tapering 
  

   more 
  or 
  less, 
  the 
  middle 
  beset 
  with 
  few, 
  low, 
  and 
  rounded 
  tubercles, 
  

   more 
  or 
  less 
  roughened 
  towards 
  the 
  ends 
  ; 
  size 
  "21 
  to 
  '2o 
  by 
  '024 
  

   to 
  -030 
  millim. 
  (iv.) 
  Longitudinal 
  spicules, 
  apparently 
  almost 
  the 
  

  

  