﻿ALCTONARIA. 
  351 
  

  

  27. 
  Solanderia, 
  ? 
  sp. 
  

  

  An 
  apparently 
  dead 
  and 
  bleached 
  specimen 
  of 
  considerable 
  size 
  

   seems 
  to 
  belong 
  to 
  this 
  gonns, 
  and 
  is 
  decidedly 
  distinct 
  from 
  the 
  

   South- 
  African 
  species 
  called 
  by 
  Gray 
  Homophyton 
  (jatti/ce 
  ; 
  but 
  I 
  

   prefer 
  to 
  await 
  better 
  specimens 
  before 
  describing 
  it, 
  as 
  members 
  of 
  

   this 
  family 
  appear 
  to 
  rapidly 
  lose 
  their 
  natural 
  characters 
  when 
  

   dying 
  in 
  the 
  sea. 
  

  

  Ilab. 
  Thursday 
  Island, 
  Torres 
  Straits, 
  4-5 
  fms. 
  

  

  ICILIGORGIA. 
  

  

  Drichassainq 
  de 
  Fo)ihressin, 
  Revue 
  des 
  Zoophytes 
  et 
  des 
  Spongiaires 
  dcs 
  

   Antilles 
  (Paris, 
  1870), 
  p. 
  13. 
  

  

  Central 
  spicular 
  axis 
  dense, 
  imperforate. 
  Longitudinal 
  canals 
  

   forming 
  a 
  circumaxial 
  zone. 
  Erect, 
  branched 
  ; 
  stem 
  and 
  branches 
  

   antero-laterally 
  compressed, 
  with 
  knife-like 
  lateral 
  edges. 
  Zooids 
  

   wholly 
  retractile, 
  arranged 
  in 
  single 
  series 
  along 
  each 
  edge 
  of 
  the 
  

   branches 
  ; 
  no 
  external 
  verruca?. 
  

  

  To 
  this 
  hitherto 
  exclusively 
  AYest-Indian 
  genus 
  appears 
  to 
  belong 
  

   the 
  following 
  species 
  : 
  — 
  

  

  28. 
  Iciligorgia 
  orientalis. 
  (Plate 
  XXXYII. 
  figs. 
  F-F", 
  

   and 
  Plate 
  XXXVIII. 
  fig. 
  e.) 
  

  

  Stem 
  long, 
  slender, 
  transverselj" 
  expanded, 
  with 
  a 
  median 
  rounded 
  

   ridge 
  running 
  down 
  each 
  of 
  the 
  anterior 
  and 
  posterior 
  faces 
  ; 
  the 
  

   lateral 
  margins 
  forming 
  two 
  even 
  knife-like 
  edges, 
  in 
  grooves 
  in 
  

   v.'hich 
  the 
  zooids 
  lie. 
  Branching 
  ai:)parently 
  normally 
  dichotomous, 
  

   in 
  same 
  plaiie 
  as 
  the 
  long 
  diameter 
  of 
  the 
  stem. 
  Branches 
  oval, 
  trans- 
  

   versely 
  expanded, 
  like 
  the 
  stem, 
  but 
  without 
  the 
  median 
  rounded 
  

   ridge 
  possessed 
  by 
  the 
  stem, 
  except 
  near 
  the 
  origins 
  of 
  the 
  main 
  

   branches. 
  The 
  transverse 
  diameter 
  of 
  both 
  stem 
  and 
  branches 
  is 
  to 
  

   the 
  antero-posterior 
  as 
  2 
  : 
  1. 
  Surface 
  even, 
  feeling 
  shghtly 
  rough 
  to 
  

   the 
  finger. 
  Zooids 
  uniserially 
  arranged, 
  about 
  -5 
  millim. 
  in 
  dia- 
  

   meter, 
  "5 
  millim. 
  apart, 
  set 
  in 
  a 
  narrow 
  continuous 
  lateral 
  groove 
  of 
  

   the 
  stem 
  and 
  branches. 
  Colour 
  of 
  stem 
  in 
  spirit 
  pinkish 
  yellow, 
  of 
  

   branches 
  cream-colour. 
  

  

  In 
  transverse 
  section 
  the 
  stem 
  and 
  branches 
  are 
  seen 
  to 
  consist 
  of 
  

   a 
  cylindrical 
  central 
  (" 
  medullary 
  ") 
  spicular 
  axis 
  of 
  closely 
  aggre- 
  

   gated 
  but 
  distinct 
  spicula, 
  occupying 
  from 
  four 
  fifths 
  (at 
  the 
  base 
  of 
  

   the 
  stem) 
  to 
  one 
  half 
  (at 
  the 
  apex 
  of 
  the 
  branches) 
  of 
  the 
  entire 
  

   thickness. 
  The 
  cortical 
  layer 
  is 
  similarly 
  constituted 
  ; 
  it 
  is 
  sepa- 
  

   rated 
  from 
  the 
  medulla 
  by 
  a 
  single 
  annular 
  series 
  of 
  four 
  to 
  six 
  

   circular 
  or 
  oval 
  longitudinal 
  canals, 
  varying 
  in 
  diameter 
  from 
  about 
  

   •15 
  millim. 
  near 
  the 
  terminations 
  of 
  the 
  branches 
  to 
  -3 
  millim. 
  at 
  

   the 
  base 
  of 
  the 
  stem. 
  Spicules 
  of 
  medulla, 
  chief 
  forms 
  : 
  — 
  (i.) 
  Roughly 
  

   fusiform, 
  with 
  fewirregularly 
  scattered, 
  mostly 
  fungiform, 
  compound 
  

   tubercles 
  : 
  size 
  about 
  -28 
  to 
  -45 
  by 
  -087 
  millim., 
  the 
  largest 
  tubercles 
  

   about 
  -024 
  millim. 
  in 
  height, 
  (ii.) 
  Elongated, 
  cylindrical, 
  rounded 
  

  

  