﻿438 
  COLLECTIONS 
  FROM 
  MELANESIA, 
  

  

  71. 
  Esperia 
  obscura, 
  

  

  ? 
  Carter, 
  Ann. 
  ^ 
  Mag. 
  Nat. 
  Hist. 
  1882, 
  ix. 
  p. 
  299, 
  pi. 
  xi. 
  fifj. 
  18. 
  

   ? 
  Mycale 
  grandis. 
  Gray, 
  P. 
  Z. 
  S. 
  18157, 
  p. 
  58.3 
  = 
  " 
  Eine 
  indische 
  Es- 
  

   perie," 
  Schmidt, 
  Suppl. 
  Spong. 
  Adr. 
  Meer. 
  p. 
  34, 
  pi. 
  iii. 
  fig. 
  11. 
  

  

  Mr. 
  Carter 
  assigned 
  the 
  above 
  name 
  to 
  a 
  massive 
  specimen 
  from 
  

   Freemantle, 
  S.W. 
  Australia, 
  of 
  which 
  he 
  says 
  (l. 
  c.) 
  it 
  has 
  " 
  all 
  the 
  

   characters 
  of 
  Esperia, 
  viz. 
  lace-like 
  dermal 
  layer, 
  rigid 
  interior 
  fibre, 
  

   and 
  acuate 
  (sub-pinlike) 
  form 
  of 
  skeletal 
  spicule, 
  but 
  with 
  an 
  ineijui- 
  

   anchoratc 
  about 
  5-OOOUths 
  " 
  (of 
  an 
  inch) 
  " 
  long 
  so 
  transparent 
  in 
  

   its 
  detail 
  that 
  all 
  I 
  can 
  give 
  of 
  it 
  are 
  the 
  representations 
  (pi. 
  xi. 
  

   fig. 
  18), 
  in 
  the 
  hope 
  that 
  it 
  might 
  be 
  thus 
  recognized 
  and 
  finally 
  

   illustrated." 
  In 
  the 
  present 
  collection 
  made 
  by 
  H.M.8. 
  ' 
  Alert 
  ' 
  

   occur 
  two 
  small 
  imperfect 
  specimens 
  of 
  an 
  Esperia 
  which 
  has 
  (besides 
  

   a 
  larger 
  one) 
  a 
  small 
  inequianchorate 
  spicule 
  which 
  strongly 
  resembles 
  

   Mr. 
  Carter's 
  figures 
  above 
  referred 
  to, 
  and 
  does 
  not 
  contradict 
  in 
  

   any 
  point 
  the 
  other 
  parts 
  of 
  the 
  short 
  description 
  which 
  was 
  all 
  

   that 
  Mr. 
  Cai'ter 
  was 
  able 
  to 
  give 
  of 
  his 
  species. 
  I 
  therefore 
  pro- 
  

   pose 
  to 
  refer 
  the 
  present 
  specimens 
  to 
  that 
  species 
  provisionally 
  

   until 
  other 
  specimens 
  are 
  obtained 
  from 
  Freemantle 
  or 
  its 
  neigh- 
  

   bourhood 
  which 
  may 
  clear 
  up 
  the 
  question 
  of 
  identity. 
  The 
  following 
  

   is 
  a 
  description 
  of 
  the 
  ' 
  Alert 
  ' 
  species 
  ; 
  it 
  may 
  be 
  taken 
  as 
  charac- 
  

   teristic, 
  so 
  far 
  as 
  the 
  more 
  minute 
  characters 
  go, 
  the 
  tissues 
  being 
  

   in 
  a 
  good 
  state 
  of 
  preservation 
  : 
  — 
  

  

  Sponge 
  massive, 
  enclosing 
  detached 
  (and 
  perhaps 
  fixed) 
  foreign 
  

   bodies. 
  Texture 
  firm, 
  rather 
  brittle. 
  Surface 
  gently 
  undulating, 
  

   glabrous. 
  Vents 
  numerous, 
  oval, 
  1 
  to 
  2*5 
  millim. 
  in 
  greatest 
  dia- 
  

   meter, 
  scattered 
  on 
  general 
  surface 
  ; 
  margins 
  thin, 
  sometimes 
  pro- 
  

   jecting 
  somewhat 
  ; 
  main 
  excretory 
  canals 
  rising 
  from 
  a 
  distance 
  

   below 
  the 
  surface. 
  Dermal 
  membrane 
  thin, 
  glabrous, 
  semitrans- 
  

   parent, 
  firm. 
  Colour 
  in 
  spirit 
  pale 
  dull 
  brown. 
  

  

  Main 
  skeleton 
  — 
  spiculo-fibre 
  moderately 
  well 
  defined, 
  delicate, 
  

   branching 
  at 
  various 
  angles, 
  from 
  5 
  to 
  10 
  spicules 
  broad. 
  Dermal 
  

   skeleton 
  diffuse, 
  the 
  spicules 
  scarcely 
  ever 
  arranged 
  into 
  definite 
  

   tracts, 
  but 
  loosely 
  matted. 
  Sarcode 
  thin, 
  very 
  pale 
  yellow-brown, 
  

   slightly 
  granular. 
  

  

  Spicules: 
  — 
  (1) 
  Skeleton 
  subspinulate, 
  straight 
  or 
  slightly 
  curved, 
  

   head 
  elongate, 
  subterminal, 
  slight, 
  gradually 
  passing 
  into 
  a 
  bluntly- 
  

   rounded 
  narrower 
  extremity 
  on 
  the 
  one 
  hand, 
  and 
  into 
  the 
  shaft 
  on 
  

   the 
  other 
  ; 
  diameter 
  of 
  head 
  decidedly 
  less 
  than 
  that 
  of 
  shaft 
  ; 
  shaft 
  

   tapering 
  gradually 
  to 
  within 
  about 
  three 
  diameters 
  of 
  apex 
  and 
  then 
  

   rapidly 
  to 
  a 
  sharp 
  point; 
  size 
  -8 
  by 
  •014miUim. 
  (2) 
  Large 
  inequi- 
  

   anchorate 
  ; 
  shaft 
  slightly 
  curved, 
  stout 
  ; 
  larger 
  end 
  of 
  spicule 
  of 
  same 
  

   longitudinal 
  and 
  horizontal 
  diameter, 
  viz. 
  one 
  third 
  as 
  much 
  as 
  total 
  

   length 
  of 
  spicule 
  ; 
  lateral 
  palms 
  finely 
  curved, 
  ending 
  below 
  in 
  

   sharp 
  inwardly-curved 
  points 
  and 
  reduced 
  to 
  narrow 
  falciform 
  pro- 
  

   cesses 
  with 
  a 
  narrow 
  reverted 
  rim 
  as 
  seen 
  from 
  front 
  ; 
  anterior 
  palm 
  

   oblong, 
  with 
  rounded 
  angles 
  as 
  seen 
  from 
  front 
  ; 
  tubercle 
  distinct, 
  

   oval 
  ; 
  smaller 
  end 
  of 
  spicule 
  with 
  abrupt 
  square 
  upper 
  margin 
  ; 
  

  

  