﻿476 
  COLLECTIONS 
  FROM 
  MELANESIA. 
  

  

  103. 
  Stelletta, 
  sp. 
  

  

  Some 
  fragments 
  of 
  a 
  large 
  specimen 
  which 
  has 
  grown 
  over 
  

   some 
  coils 
  of 
  Vermetus, 
  not 
  sufficiently 
  complete 
  to 
  be 
  safely- 
  

   described 
  in 
  full. 
  The 
  stellates 
  are 
  minute, 
  and 
  resemble 
  those 
  of 
  

   S. 
  purpurea 
  and 
  clavosa, 
  but 
  the 
  arms 
  are 
  somewhat 
  stouter 
  and 
  are 
  

   not 
  provided 
  with 
  heads. 
  

  

  Hah. 
  Torres 
  Straits, 
  5-7 
  fms. 
  

  

  STELLETTINOPSIS. 
  

  

  Carter, 
  Ann. 
  ^ 
  May. 
  N. 
  H. 
  1879, 
  iii. 
  p. 
  348. 
  

  

  This 
  genus 
  resembles 
  Tetliyopsis, 
  Stewart, 
  in 
  that 
  the 
  two 
  typical 
  

   species 
  have 
  a 
  minute 
  bacillar 
  flesh-spicule 
  just 
  such 
  as 
  that 
  of 
  the 
  

   new 
  species 
  of 
  Tethyopsis 
  described 
  below 
  ; 
  and 
  if 
  it 
  be, 
  as 
  seems 
  

   probable, 
  a 
  tetractinellid 
  which 
  has 
  undergone 
  abortion 
  of 
  two 
  arms 
  

   (as 
  in 
  Placina 
  monolophn^ 
  Schulze) 
  of 
  the 
  main 
  spicule, 
  it 
  resembles 
  

   Tethyopsis 
  further 
  in 
  this 
  tendency 
  to 
  lose 
  the 
  arms 
  of 
  its 
  skeleton- 
  

   spicule 
  (see 
  description 
  of 
  Tethyopsis 
  dissimilis, 
  supra). 
  Eeduction 
  

   of 
  the 
  triradiate 
  of 
  the 
  latter 
  species 
  by 
  loss 
  of 
  a 
  single 
  arm 
  would 
  

   make 
  the 
  spiculation 
  (apart 
  from 
  the 
  skeleton-arrangement) 
  essen- 
  

   tially 
  that 
  of 
  l^tellettinopsis, 
  if 
  the 
  bacillar 
  spicule 
  is 
  regarded 
  as 
  

   an 
  elongate 
  stellate. 
  The 
  new 
  species 
  is 
  assigned 
  here 
  to 
  Stelletti- 
  

   nopsis 
  because 
  it 
  differs 
  only 
  from 
  the 
  typical 
  species 
  in 
  the 
  absence 
  

   of 
  the 
  bacillar,- 
  — 
  not 
  a 
  point 
  of 
  great 
  importance, 
  if 
  the 
  variation 
  

   in 
  Geodia 
  as 
  to 
  presence 
  and 
  absence 
  of 
  one 
  or 
  other 
  of 
  the 
  minute 
  

   spicules 
  is 
  considered. 
  

  

  I 
  dedicate 
  this 
  new 
  species 
  to 
  Mr. 
  H. 
  J. 
  Carter, 
  to 
  whom 
  is 
  due 
  

   the 
  credit 
  of 
  establishing 
  this 
  genus, 
  and 
  to 
  whom 
  I 
  owe 
  a 
  great 
  

   debt 
  in 
  his 
  constant 
  and 
  ready 
  help. 
  

  

  104. 
  Stellettinopsis 
  carteri. 
  (Plate 
  XLIII. 
  figs, 
  n, 
  n.) 
  

  

  Pedicellate, 
  on 
  a 
  short 
  cylindrical 
  stalk, 
  passing 
  gradually 
  into 
  

   a 
  massive, 
  somewhat 
  flattened 
  upper 
  portion, 
  which 
  shows 
  semi- 
  

   detached 
  lobes. 
  Surface 
  of 
  upper 
  portion 
  dimjiled 
  and 
  corrugated 
  

   (somewhat 
  like 
  the 
  Mammalian 
  cerebrum). 
  No 
  visible 
  vents. 
  Tex- 
  

   ture 
  in 
  spirit 
  soft, 
  but 
  elastic 
  ; 
  colour 
  in 
  spirit 
  dirty 
  white. 
  Sur- 
  

   face 
  between 
  the 
  undulations 
  even, 
  but 
  minutely 
  rough. 
  Sarcode 
  

   continuous, 
  without 
  many 
  cavities 
  ; 
  soft, 
  very 
  pale 
  yellow 
  in 
  colour. 
  

   Main 
  and 
  dermal 
  skeletons 
  consisting 
  of 
  a 
  confused 
  interlacement 
  

   of 
  the 
  skeleton 
  acerate 
  spicules, 
  not 
  aggregated 
  into 
  fibres 
  or 
  tracts. 
  

  

  Spicules: 
  — 
  (1) 
  Skeleton 
  acerate, 
  taperiug 
  to 
  sharp 
  points 
  from 
  

   near 
  the 
  middle 
  ; 
  size 
  1-0 
  by 
  -02 
  millim. 
  (2) 
  Stellate, 
  with 
  very 
  

   slight 
  body, 
  and 
  five 
  to 
  ten 
  straight 
  blunt 
  arms 
  of 
  uniform 
  dia- 
  

   meter 
  (about 
  -0017 
  millim.) 
  throughout 
  ; 
  microspined 
  with 
  fine 
  sharp 
  

   points, 
  which 
  are 
  most 
  prominent 
  at 
  the 
  tips 
  ; 
  size 
  -05 
  millim. 
  

   across 
  arms. 
  

  

  Hah. 
  Prince 
  of 
  Wales 
  Channel, 
  Torres 
  Straits, 
  5-7 
  fms. 
  ; 
  bottom 
  

   sand 
  and 
  shells. 
  

  

  