﻿ALCrOXAEIA. 
  357 
  

  

  carefully 
  and 
  found 
  that, 
  in 
  the 
  proportion 
  of 
  about 
  1 
  to 
  30 
  of 
  the 
  

   ordinary 
  verrucas, 
  or 
  about 
  one 
  to 
  each 
  internode, 
  some 
  large 
  verrucse 
  

   occurred, 
  about 
  twipe 
  the 
  diameter 
  of 
  the 
  usual 
  forms 
  ; 
  this 
  was 
  the 
  

   case 
  only 
  on 
  the 
  medium-sized 
  and 
  larger 
  branches. 
  Unfortunately 
  

   no 
  spirit-specimens 
  of 
  the 
  species 
  were 
  obtained 
  ; 
  but 
  the 
  exami- 
  

   nation 
  of 
  the 
  open 
  verrucas 
  shows 
  8 
  short 
  spiculate 
  tentacle-lobes, 
  

   converging 
  like 
  the 
  segments 
  of 
  an 
  orange, 
  within 
  both 
  the 
  smaller 
  

   and 
  larger 
  verrucas. 
  This 
  is 
  therefore 
  a 
  case 
  of 
  dimorphism 
  much 
  

   less 
  strongly 
  marked 
  than 
  and 
  of 
  a 
  different 
  character 
  from 
  that 
  of 
  

   the 
  Penuatulida, 
  and 
  of 
  CoralUum 
  and 
  SarcopJit/tum, 
  where 
  the 
  

   asexual 
  zooids 
  have 
  no 
  tentacles. 
  Possibly, 
  when 
  spirit-specimens 
  

   are 
  examined, 
  it 
  will 
  be 
  found 
  that 
  these 
  two 
  kinds 
  of 
  tentaculate 
  

   individuals 
  represent 
  the 
  two 
  kinds 
  of 
  "polypes" 
  (viz. 
  rudimentary 
  

   sexual 
  and 
  perfect 
  asexual) 
  which 
  occur 
  in 
  Hcdisceptrum 
  (Kolliker, 
  

   • 
  Pennatulidcu,' 
  p. 
  161) 
  in 
  addition 
  to 
  the 
  sexual 
  " 
  zooids." 
  

  

  In 
  my 
  descriptions 
  I 
  have 
  employed 
  the 
  term 
  " 
  internode 
  " 
  for 
  

   the 
  hard 
  joints, 
  and 
  " 
  soft 
  joints 
  " 
  for 
  the 
  intermediate 
  ones, 
  as 
  being 
  

   more 
  appropriate 
  and 
  more 
  conformable 
  to 
  the 
  botanical 
  usage 
  than 
  

   the 
  "joint" 
  and 
  "internode" 
  employed 
  by 
  Gray 
  (I.e.) 
  to 
  designate 
  

   these 
  parts 
  respectively. 
  

  

  The 
  new 
  genus 
  Psilacaharla 
  presents 
  an 
  exception 
  to 
  the 
  usually 
  

   strongly 
  marked 
  bilateral 
  symmetry 
  in 
  the 
  arrangement 
  of 
  the 
  

   external 
  parts 
  of 
  the 
  corallum 
  in 
  this 
  family. 
  

  

  MELITODES. 
  

  

  Melitsea, 
  Lamarck, 
  Mem. 
  du 
  Miis. 
  d'Hist. 
  Nat. 
  i. 
  p. 
  410 
  (1815). 
  

   Melitodes, 
  Verrill, 
  Bull. 
  Mus. 
  Comp. 
  Zool. 
  i. 
  p. 
  38 
  (1863). 
  

  

  Axis, 
  both 
  hard 
  and 
  soft 
  joints, 
  traversed 
  by 
  longitudinal 
  canals 
  ; 
  

   cortical 
  spicules 
  of 
  two 
  kinds, 
  viz. 
  larger, 
  fusiform, 
  verrucose, 
  and 
  

   smaller, 
  nodular, 
  iis 
  above 
  stated, 
  the 
  first 
  of 
  these 
  characters 
  only 
  

   distinguishes 
  Melitodes 
  from 
  Glathraria 
  and 
  Psilacaharia 
  among 
  

   Melithseidse. 
  

  

  32. 
  Melitodes 
  albitincta. 
  

  

  (Plate 
  XXXVII. 
  figs. 
  C-C" 
  ; 
  Plate 
  XXXVIII. 
  figs. 
  6, 
  h' 
  .) 
  

  

  Corallum 
  slight, 
  branching 
  in 
  one 
  plane. 
  Stem 
  slender, 
  internodes 
  

   circular 
  in 
  section 
  ; 
  joints 
  oval, 
  little 
  thicker 
  than 
  the 
  internodes 
  and 
  

   about 
  half 
  their 
  length. 
  Branchlets 
  slender, 
  undulating, 
  almost 
  all 
  

   anastomosing, 
  forming 
  chiefly 
  elongate 
  meshes. 
  Diameter 
  of 
  inter- 
  

   nodes 
  of 
  the 
  larger 
  main 
  branches 
  3 
  millim., 
  of 
  terminal 
  branchlets 
  

   1 
  millim. 
  Colour 
  of 
  general 
  cortex 
  in 
  dry 
  state 
  white, 
  beautifully 
  

   speckled 
  with 
  vermilion, 
  that 
  of 
  verruc;ie 
  and 
  the 
  contained 
  polypes 
  

   orange-yellow. 
  Cortex 
  very 
  smooth, 
  thin 
  on 
  stem, 
  on 
  terminal 
  

   branchlets 
  forming 
  about 
  two 
  thirds 
  of 
  the 
  thickness 
  of 
  the 
  branch. 
  

   Verrucoe 
  broad, 
  slightly 
  prominent, 
  arranged 
  in 
  two 
  alternating 
  rows 
  

   on 
  each 
  side 
  of 
  the 
  brunches, 
  but 
  generally 
  absent 
  from 
  the 
  anterior 
  

   and 
  posterior 
  faces 
  ; 
  they 
  are 
  of 
  two 
  sizes, 
  viz. 
  : 
  — 
  (i.) 
  abundant, 
  low, 
  

   about 
  '4 
  millim. 
  in 
  diameter 
  at 
  their 
  base 
  ; 
  (ii.) 
  about 
  one 
  to 
  each 
  

   internode 
  on 
  an 
  average, 
  more 
  prominent 
  than 
  (i.), 
  measuring 
  about 
  

  

  