﻿the 
  Gulf 
  of 
  Man 
  aar. 
  81 
  

  

  specimen 
  135 
  millim.) 
  The 
  oscula 
  are 
  rather 
  large, 
  com- 
  

   monly 
  about 
  4 
  millim. 
  in 
  diameter 
  in 
  well-grown 
  specimens 
  ; 
  

   they 
  occur 
  on 
  one 
  surface 
  only 
  of 
  the 
  lamellae 
  and 
  sometimes 
  

   round 
  the 
  margin. 
  The 
  dermal 
  membrane 
  is 
  distinct, 
  with 
  a 
  

   well-developed 
  reticulation 
  of 
  spicnlo-fibre. 
  

  

  The 
  colour 
  in 
  life 
  was 
  pale 
  yellow 
  ; 
  when 
  dry 
  it 
  is 
  brownish 
  

   yellow, 
  and 
  the 
  same 
  colour, 
  only 
  darker, 
  in 
  spirit. 
  Texture 
  

   in 
  the 
  dry 
  state 
  tough 
  and 
  hard, 
  but 
  rather 
  open. 
  When 
  the 
  

   sponge 
  is 
  held 
  up 
  to 
  the 
  light 
  stout 
  primary 
  skeleton-fibres 
  

   are 
  seen 
  ramifying 
  upwards 
  in 
  a 
  dendritic 
  manner 
  and 
  termi- 
  

   nating 
  in 
  the 
  conuli 
  on 
  the 
  surface. 
  

  

  The 
  dermal 
  skeleton 
  is 
  a 
  quite 
  irregular 
  network 
  of 
  very 
  

   stout 
  fibres, 
  containing 
  a 
  great 
  number 
  of 
  closely 
  packed 
  

   spicules 
  whose 
  meshes 
  are 
  subdivided 
  by 
  an 
  irregular 
  network 
  

   of 
  very 
  slender 
  fibres 
  both 
  uni- 
  and 
  multispiculous. 
  

  

  The 
  main 
  skeleton 
  is 
  also 
  irregular 
  and 
  composed 
  of 
  very 
  

   stout 
  primary 
  fibres 
  about 
  0T8 
  millim. 
  in 
  diameter, 
  rather 
  

   slenderer 
  secondaries 
  and 
  slender 
  tertiaries, 
  about 
  0'015 
  millim. 
  

   in 
  diameter. 
  All 
  the 
  fibres 
  contain 
  a 
  very 
  great 
  number 
  of 
  

   spicules, 
  closely 
  packed 
  side 
  by 
  side, 
  and 
  occupying 
  almost 
  

   the 
  whole 
  thickness 
  of 
  the 
  fibre 
  ; 
  but 
  there 
  is 
  plenty 
  of 
  spon- 
  

   gin 
  uniting 
  them 
  together. 
  Spicules 
  are 
  abundantly 
  scattered 
  

   about 
  outside 
  as 
  well 
  as 
  in 
  the 
  fibres. 
  

  

  The 
  spicules 
  are 
  relatively 
  long, 
  very 
  slender 
  oxea, 
  usually 
  

   slightly 
  curved, 
  measuring 
  about 
  0*126 
  by 
  0*0017 
  millim. 
  

   They 
  are 
  gradually 
  and 
  sharply 
  pointed 
  at 
  each 
  end. 
  

  

  There 
  are 
  in 
  the 
  collection 
  four 
  dry 
  specimens 
  of 
  this 
  

   sponge 
  and 
  a 
  piece 
  in 
  spirit. 
  

  

  Svphonochalina 
  communis. 
  Carter, 
  sp. 
  

  

  1881. 
  Tubulodiyitus 
  communis, 
  Carter, 
  Ann. 
  & 
  Mag. 
  Nat. 
  Hist. 
  ser. 
  5, 
  

   vol. 
  vii. 
  p. 
  3t>7. 
  

  

  With 
  this 
  species 
  I 
  identify 
  a 
  single 
  fine 
  specimen 
  attached 
  

   to 
  a 
  fragment 
  of 
  rock, 
  to 
  which 
  is 
  also 
  attached 
  a 
  small 
  

   specimen 
  of 
  Hircinia 
  clathrata. 
  The 
  sponge 
  consists 
  of 
  a 
  

   thin 
  incrusting 
  basal 
  mass, 
  spreading 
  over 
  the 
  surface 
  of 
  the 
  

   rock 
  aud 
  throwing 
  out 
  abundant 
  short, 
  upright, 
  tubular 
  pro- 
  

   cesses, 
  each 
  terminating 
  in 
  a 
  single 
  osculum. 
  The 
  tubes 
  

   reach 
  some 
  70 
  millim. 
  in 
  maximum 
  height 
  and 
  the 
  oscula 
  

   average 
  about 
  4 
  millim. 
  in 
  diameter. 
  The 
  tubes 
  anastomose 
  

   freely 
  with 
  one 
  another 
  and 
  also 
  branch 
  to 
  some 
  extent 
  ; 
  

   they 
  average 
  about 
  5 
  or 
  6 
  millim. 
  in 
  diameter. 
  

  

  The 
  colour 
  in 
  life 
  was 
  bluish 
  brown 
  • 
  in 
  spirit 
  it 
  is 
  yellowish 
  

   brown, 
  and 
  when 
  dry 
  the 
  same 
  with 
  a 
  decidedly 
  purplish 
  

  

  