﻿SPONGIIBA. 
  G29 
  

  

  55. 
  Leucortis 
  anguinea 
  *. 
  

   (Plate 
  LIII. 
  fig. 
  L; 
  Plate 
  LIV. 
  figs, 
  d, 
  d.) 
  

  

  Erect, 
  branched; 
  stem 
  and 
  branches 
  cylindrical, 
  tubnlar. 
  (Yent 
  

   opening 
  probably 
  at 
  end 
  of 
  tube 
  and 
  nearly 
  as 
  wide 
  as 
  tube.) 
  

   Branches 
  given 
  off 
  at 
  angle 
  of 
  about 
  140° 
  with 
  each 
  other. 
  Wall 
  

   •25 
  to 
  -35 
  millim. 
  thick 
  ; 
  lumen 
  of 
  tube 
  '8 
  to 
  1-2 
  millim. 
  in 
  diameter. 
  

   Outer 
  and 
  inner 
  surfaces 
  even, 
  smooth. 
  Consistence 
  in 
  spirit 
  elastic, 
  

   compressible 
  (colour 
  probably 
  white 
  or 
  grey 
  naturally, 
  at 
  present 
  

   pale 
  purple, 
  probably 
  derived 
  from 
  other 
  sponges). 
  Skeleton 
  mainly 
  

   composed 
  of 
  triradiate 
  spicules 
  ; 
  those 
  (1) 
  of 
  outer 
  surface 
  sagittal, 
  

   with 
  large 
  facial 
  angle, 
  viz. 
  150° 
  to 
  170°, 
  the 
  distal 
  three 
  fourths 
  of 
  

   the 
  lateral 
  rays 
  being, 
  in 
  the 
  latter 
  case, 
  bent 
  back 
  so 
  as 
  to 
  be 
  

   nearly 
  in 
  a 
  line 
  with 
  each 
  other 
  ; 
  basal 
  ray 
  about 
  •28 
  millim. 
  long, 
  

   laterals 
  -16 
  to 
  ^22, 
  diameter 
  of 
  rays 
  at 
  base 
  •OlS 
  to 
  -019 
  millim. 
  

   Surface 
  triradiates 
  occasionally 
  provided 
  with 
  a 
  short 
  stout 
  apical 
  

   ray. 
  (2) 
  Triradiates 
  of 
  inner 
  and 
  central 
  part 
  of 
  wall 
  either 
  

   sagittal, 
  with 
  facial 
  angle 
  of 
  about 
  140°, 
  the 
  rays 
  as 
  in 
  the 
  surface- 
  

   spicules, 
  or 
  subregular, 
  the 
  angles 
  being 
  about 
  120° 
  each 
  and 
  the 
  

   lateral 
  rays 
  slightly 
  unequal 
  ; 
  in 
  both 
  cases 
  the 
  lengths 
  and 
  diameters 
  

   of 
  the 
  rays 
  as 
  in 
  the 
  surface-spicules. 
  Eays 
  of 
  triradiates, 
  except 
  

   in 
  the 
  case 
  above 
  mentioned, 
  almost 
  straight, 
  tapering 
  from 
  base 
  to 
  

   point. 
  (3) 
  Linear 
  spicules 
  of 
  general 
  body- 
  wall, 
  stout, 
  fusiform, 
  

   acerate, 
  slightly 
  curved, 
  tapering 
  equally 
  to 
  similarly 
  sharp 
  points 
  

   at 
  both 
  ends; 
  size 
  -65 
  by 
  '032 
  millim.; 
  scattered 
  singly 
  at 
  right 
  

   angles 
  to 
  surface, 
  points 
  not 
  projecting 
  except 
  at 
  peristome 
  slightly. 
  

   (4) 
  Fine 
  acerate 
  ? 
  of 
  peristome, 
  length 
  probably 
  about 
  ^22 
  millim., 
  

   thickness 
  -0032 
  millim. 
  ; 
  closely 
  aggregated 
  at 
  outer 
  surface, 
  at 
  right 
  

   angles 
  to 
  surface 
  (the 
  inner 
  end 
  is 
  sharp, 
  the 
  outer 
  end 
  has 
  not 
  been 
  

   observed). 
  Canals 
  leading 
  from 
  cloacal 
  cavity 
  small 
  : 
  chambers 
  of 
  

   canal-system 
  small, 
  inconspicuous. 
  Spicides 
  of 
  centre 
  of 
  wall 
  densely 
  

   aggregated. 
  

  

  Hab. 
  Providence 
  Reef, 
  Mascarene 
  group, 
  24 
  fms, 
  ; 
  bottom, 
  sand 
  

   and 
  dead 
  coral. 
  

  

  A 
  single 
  specimen, 
  imperfect 
  at 
  both 
  extremities, 
  represents 
  the 
  

   species. 
  It 
  is 
  25 
  millim. 
  in 
  height, 
  and 
  consists 
  of 
  a 
  short 
  common 
  

   stem 
  and 
  of 
  two 
  branches, 
  little 
  inferior 
  to 
  the 
  stem 
  in 
  diameter, 
  one 
  

   of 
  them 
  even 
  increasing 
  in 
  diameter 
  towards 
  its 
  termination. 
  

  

  From 
  the 
  occurrence 
  of 
  the 
  fine 
  linear 
  spicules 
  in 
  some 
  of 
  the 
  first 
  

   sections 
  which 
  were 
  made 
  it 
  is 
  inferred 
  that 
  they 
  were 
  from 
  a 
  peri- 
  

   stome, 
  which 
  was 
  probably 
  almost 
  as 
  wide 
  as 
  the 
  tube 
  and 
  had 
  a 
  

   slight 
  fringe. 
  The 
  occurrence 
  of 
  a 
  few 
  quadriradiates 
  has 
  been 
  

   observed 
  also 
  in 
  the 
  only 
  species 
  assigned 
  by 
  Hackel 
  to 
  the 
  genus, 
  

   viz. 
  L. 
  lyulvinar, 
  Hackel; 
  and 
  thus, 
  if 
  Haekel's 
  terms 
  were 
  em- 
  

   ployed, 
  this 
  specimen 
  would 
  be 
  distinguishable 
  as 
  a 
  " 
  connecting 
  

   variety 
  " 
  under 
  the 
  name 
  Leucandra 
  ayiguincus. 
  This 
  species 
  is 
  

   markedly 
  distinct 
  from 
  L. 
  pidvinar 
  in 
  its 
  slender 
  form, 
  in 
  the 
  

   relatively 
  small 
  size 
  of 
  the 
  acerate 
  spicules 
  of 
  the 
  body- 
  wall, 
  and 
  in 
  

  

  * 
  Atlguineus, 
  snake-like, 
  from 
  the 
  elongate 
  pliable 
  character 
  of 
  the 
  specimens. 
  

  

  