﻿602 
  COLLECTIONS 
  PKOM 
  THE 
  WESTERN 
  INDIAN 
  OCEAN. 
  

  

  GUMMINID^. 
  

  

  Gummineae, 
  Schmidt, 
  Sjjotiff. 
  Kdst. 
  Alg. 
  p. 
  1. 
  

  

  Gumminida, 
  Carter, 
  Ann. 
  l^- 
  Mag. 
  N. 
  H. 
  1881, 
  viii. 
  p. 
  248. 
  

  

  I 
  retain 
  this 
  group 
  provisionally 
  at 
  the 
  commencement 
  of 
  the 
  

   Silicea, 
  but 
  believe 
  it 
  will 
  ultimately 
  have 
  to 
  be 
  placed 
  near 
  the 
  

   Tetractinellida. 
  

  

  18. 
  Chondrilla 
  mixta. 
  

  

  ? 
  Chondrilla 
  mixta, 
  Schulze, 
  Zeitsch. 
  wiss. 
  Zool. 
  xxix. 
  p. 
  116. 
  

  

  Prof. 
  Schulze's 
  description 
  of 
  his 
  species 
  is 
  scarcely 
  sufficient 
  for 
  

   mc 
  to 
  determine 
  its 
  relations 
  to 
  the 
  present 
  specimen, 
  as 
  he 
  does 
  

   not 
  mention 
  the 
  size 
  and 
  exact 
  form 
  of 
  the 
  spicules. 
  It 
  agrees 
  

   with 
  the 
  present 
  form 
  in 
  having 
  two 
  kinds 
  of 
  spicules, 
  stellates 
  and 
  

   globostellates, 
  in 
  having 
  a 
  fibrous 
  outer 
  layer 
  about 
  1 
  millim. 
  thick, 
  

   and 
  in 
  the 
  distribution 
  of 
  the 
  spicules 
  in 
  the 
  substance. 
  On 
  the 
  

   other 
  hand 
  the 
  sections 
  of 
  this 
  (very 
  young) 
  specimen 
  exhibit 
  but 
  

   scanty 
  traces 
  of 
  the 
  system 
  of 
  subcortical 
  canals 
  which 
  appears 
  to 
  

   be 
  so 
  well 
  developed 
  in 
  the 
  Red-Sea 
  species, 
  and 
  the 
  colour 
  (in 
  

   spirit) 
  is 
  pale 
  brown 
  or 
  buff 
  rather 
  than 
  " 
  pale 
  grey, 
  speckled 
  with 
  

   brown." 
  The 
  stellate 
  spicules 
  have 
  rather 
  coarse 
  rays 
  which 
  often 
  

   bifurcate, 
  as 
  in 
  C. 
  cmstraliensis, 
  Carter 
  ; 
  they 
  measure 
  -025 
  millim. 
  

   in 
  diameter, 
  the 
  globostellates 
  -032 
  millim. 
  Having 
  regard 
  to 
  the 
  

   nearness 
  of 
  the 
  two 
  localities, 
  and 
  to 
  the 
  points 
  of 
  positive 
  agreement 
  

   between 
  the 
  present 
  specimen 
  and 
  Schulze's 
  species, 
  I 
  am 
  disposed 
  

   to 
  consider 
  them 
  to 
  be 
  identical. 
  The 
  present 
  specimen 
  differs 
  from 
  

   C 
  australiensis 
  in 
  the 
  relatively 
  longer 
  and 
  more 
  slender 
  arms 
  of 
  

   the 
  stellate 
  (radiostellate 
  of 
  Carter), 
  the 
  greater 
  abundance 
  of 
  the 
  

   spicules 
  in 
  the 
  subcortical 
  tissues, 
  and 
  the 
  larger 
  size 
  of 
  both 
  spicules 
  

   (in 
  0. 
  australiensis 
  the 
  globostellate 
  measures 
  •025, 
  the 
  stellate 
  

   about 
  '02 
  millim.). 
  

  

  A 
  very 
  small 
  specimen, 
  about 
  5 
  millim. 
  across, 
  on 
  a 
  N'uUipore 
  

   which 
  has 
  been 
  partly 
  overgrown 
  by 
  a 
  repent 
  Ghalina. 
  

  

  Hah. 
  Marie 
  Louise 
  Island, 
  Amirante 
  group, 
  16-17 
  fms. 
  

  

  Distribution. 
  Red 
  Sea 
  {Schulze) 
  ? 
  

  

  CHALINID^. 
  

  

  The 
  percentage 
  of 
  species 
  of 
  Chalinidoe 
  in 
  this 
  collection 
  is 
  small 
  

   for 
  the 
  Tropics, 
  viz. 
  less 
  than 
  8 
  per 
  cent., 
  that 
  of 
  the 
  ChalinidDe 
  in 
  

   the 
  Australian 
  collections 
  being 
  15 
  per 
  cent. 
  This 
  inferiority 
  in 
  

   numbers 
  is 
  duo 
  in 
  part 
  to 
  the 
  absence 
  of 
  the 
  tubular 
  forms, 
  which 
  

   are 
  represented 
  by 
  Tuba, 
  Siplionochalina, 
  and 
  Tubuhdigitus 
  near 
  

   Australia, 
  and 
  chiefly 
  by 
  Tuba 
  in 
  the 
  West 
  Indies. 
  As, 
  however, 
  

   Siphonochalina 
  occurs 
  both 
  at 
  the 
  Cape 
  (Ehlers) 
  and 
  the 
  Red 
  Sea 
  

   {British- 
  Museum 
  collection), 
  it 
  probably 
  will 
  be 
  ultimately 
  found 
  

   also 
  in 
  the 
  intervening 
  district. 
  If 
  the 
  wide-mouthed 
  genus 
  Tuba 
  

   is 
  really 
  absent 
  here, 
  the 
  circumstance 
  is 
  of 
  considerable 
  import- 
  

   ance, 
  as 
  it 
  seems 
  to 
  be 
  represented 
  abundantly 
  in 
  the 
  tropical 
  parts 
  

   of 
  both 
  sides 
  of 
  the 
  American 
  continent 
  and 
  in 
  the 
  Malay 
  archi- 
  

  

  