﻿402 
  COLLEGTIUNS 
  FROM 
  MELANESIA. 
  

  

  resemblance 
  in 
  external 
  characters 
  and 
  in 
  this 
  remarkable 
  structural 
  

   point 
  between 
  Mr. 
  Carter's 
  species 
  and 
  the 
  present 
  specimens, 
  I 
  

   assign 
  the 
  latter 
  with 
  little 
  doubt 
  to 
  that 
  species, 
  although 
  Mr. 
  

   Carter 
  has 
  not 
  given 
  the 
  measurements 
  of 
  the 
  spicules. 
  

  

  Hah. 
  Port 
  Jackson, 
  0-5 
  fms. 
  

  

  Distrihution. 
  Ceylon 
  {Carter) 
  ; 
  Kurrachee 
  {coll. 
  Mus. 
  Brit.). 
  

  

  The 
  absence 
  of 
  this 
  species 
  from 
  the 
  hauls 
  made 
  in 
  the 
  tropical 
  

   waters 
  of 
  Northern 
  Australia 
  perhaps 
  indicates 
  that 
  its 
  natural 
  

   habitat 
  is 
  in 
  subtropical 
  seas, 
  like 
  those 
  of 
  Northern 
  India 
  and 
  Port 
  

   Jackson. 
  

  

  TOXOCHALINA*, 
  g. 
  n. 
  

  

  Clialinidae 
  with 
  well-developed 
  horny 
  fibre 
  arranged 
  rectangularly. 
  

   Spicules, 
  a 
  skeleton 
  acerate 
  and 
  a 
  tricurvate 
  acerate 
  (" 
  Bogen," 
  

   German) 
  flesh-spicule. 
  

  

  Obs. 
  The 
  tricurvate 
  flesh-spicule 
  distinguishes 
  this 
  genus 
  from 
  all 
  

   other 
  Chalinidse; 
  the 
  only 
  parallels 
  for 
  the 
  occurrence 
  of 
  a 
  flesh- 
  

   spicule 
  in 
  this 
  group 
  with 
  which 
  I 
  am 
  acquainted 
  are 
  found 
  in 
  the 
  

   species 
  Halichondria 
  palmata 
  of 
  Johnston, 
  lately 
  (Ann. 
  & 
  Mag. 
  Nat. 
  

   Hist. 
  (5) 
  X. 
  p. 
  109) 
  redescribed 
  and 
  assigned 
  by 
  Mr. 
  Carter 
  to 
  the 
  

   genus 
  CJialina, 
  and 
  Spongia 
  {Desmacidon, 
  Ehlers) 
  compressa., 
  Esper, 
  

   also 
  referred 
  {I. 
  c. 
  p. 
  112) 
  by 
  Mr. 
  Carter 
  to 
  Chalina, 
  and 
  in 
  a 
  species 
  

   described 
  by 
  0. 
  Schmidt 
  (' 
  Meerbus. 
  Mexico,' 
  p. 
  70) 
  as 
  Rhizochalina? 
  

   Jibidata, 
  which 
  has 
  bihamates. 
  The 
  fact 
  of 
  an 
  intimate 
  connexion, 
  

   which 
  seems 
  to 
  have 
  been 
  thus 
  already 
  discovered, 
  between 
  the 
  

   Chalinida) 
  and 
  Desmacidinidae, 
  appears 
  to 
  receive 
  confirmation 
  from 
  

   the 
  present 
  cases 
  of 
  the 
  occurrence 
  of 
  a 
  tricurvate 
  flesh-spicule 
  in 
  

   members 
  of 
  the 
  former 
  family. 
  

  

  32. 
  Toxochalina 
  folioides. 
  (Plate 
  XLI. 
  figs, 
  m-m".) 
  

   Desmacidon 
  folioides, 
  Boiverbank, 
  P. 
  Z. 
  S. 
  1875, 
  p. 
  295. 
  

  

  In 
  one 
  Bowerbankian 
  specimen 
  from 
  New 
  Guinea 
  and 
  one 
  ' 
  Alert 
  ' 
  

   specimen 
  from 
  Australia 
  the 
  form 
  is 
  vallate, 
  produced 
  by 
  the 
  lateral 
  

   union 
  of 
  a 
  series 
  of 
  tubes 
  ; 
  the 
  other 
  ' 
  Alert 
  ' 
  specimens 
  agree 
  with 
  

   the 
  type 
  (see 
  Bowerbank, 
  /. 
  c.) 
  in 
  its 
  external 
  form, 
  and 
  the 
  former 
  

   specimens 
  may 
  be 
  termed 
  var. 
  vallata. 
  This 
  is 
  a 
  true 
  Chalinid, 
  

   although 
  the 
  amount 
  of 
  horny 
  material 
  in 
  the 
  fibre 
  is 
  no 
  more 
  than 
  

   enough 
  to 
  unite 
  the 
  spicules 
  into 
  a 
  tough 
  and 
  elastic 
  mass, 
  and 
  is 
  

   not 
  visible 
  outside 
  the 
  spicules. 
  I 
  have 
  detected 
  in 
  the 
  type 
  speci- 
  

   men 
  of 
  this 
  species 
  small, 
  smooth, 
  finely-pointed, 
  tricurvate 
  acerates, 
  

   about 
  -04 
  by 
  "001 
  millim. 
  in 
  size, 
  in 
  the 
  dermal 
  membrane 
  ; 
  I 
  have 
  

   not 
  yet 
  detected 
  them 
  in 
  the 
  subjacent 
  tissues, 
  tliough 
  this 
  has 
  been 
  

   done 
  for 
  another 
  specimen 
  of 
  the 
  species 
  in 
  the 
  Bowerbankian 
  col- 
  

   lection 
  (from 
  New 
  Guinea). 
  The 
  skeleton-spicules 
  vary 
  from 
  rather 
  

   tapering 
  cylindrical, 
  with 
  rounded 
  ends, 
  to 
  tapering 
  acerate, 
  with 
  

   sharp 
  ends, 
  size 
  about 
  -11 
  by 
  '0042 
  millim. 
  in 
  the 
  typical, 
  and 
  "16 
  

   by 
  '0085 
  millim. 
  in 
  the 
  Port 
  Darwin 
  specimens. 
  The 
  New-Guinea 
  

  

  * 
  From 
  Gi". 
  t6%ov, 
  a 
  bow 
  ; 
  and 
  xaXtvos, 
  a 
  tbong. 
  

  

  