﻿166 
  COLLECTIONS 
  PKOM 
  MELANESIA, 
  

  

  foruily 
  purple, 
  while 
  the 
  other 
  has 
  the 
  purple 
  relieved 
  by 
  a 
  white 
  

   median 
  dorsal 
  line 
  and 
  by 
  some 
  white 
  pinnules. 
  

  

  I 
  trust 
  that 
  with 
  an 
  increase 
  in 
  our 
  knowledge 
  and 
  with 
  a 
  larger 
  

   series 
  of 
  specimens 
  the 
  preceding 
  discussion 
  will 
  be 
  found, 
  long 
  as 
  it 
  

   must 
  have 
  seemed, 
  to 
  be 
  of 
  some 
  aid 
  in 
  the 
  determination 
  of 
  the 
  

   characters 
  and 
  limits 
  of 
  the 
  species 
  ; 
  with 
  such 
  scanty 
  information 
  

   as 
  we 
  possess 
  at 
  present 
  it 
  would 
  be 
  to 
  the 
  last 
  degree 
  rash 
  to 
  

   venture 
  on 
  any 
  kind 
  of 
  prophesj-. 
  Were 
  I 
  to 
  make 
  one, 
  however, 
  

   I 
  should 
  say 
  that 
  many 
  of 
  the 
  variations, 
  which 
  at 
  present 
  there 
  is 
  

   a 
  tendency 
  to 
  regard 
  as 
  of 
  specific 
  importance, 
  will 
  be 
  found 
  to 
  

   present 
  less 
  constancy 
  of 
  arrangement 
  when 
  large 
  series 
  are 
  brought 
  

   together 
  for 
  examination. 
  In 
  the 
  work 
  of 
  enlarging 
  our 
  knowledge 
  

   of 
  the 
  species 
  of 
  Crinoids 
  the 
  British 
  Museum 
  may 
  well 
  look 
  to 
  

   those 
  English 
  colonists 
  who 
  live 
  on 
  such 
  sea-boards 
  as 
  that 
  of 
  the 
  

   Australian 
  coasts, 
  and 
  who 
  have 
  opportunity 
  to 
  do 
  some 
  dredging 
  

   in 
  their 
  waters. 
  

  

  The 
  student 
  will 
  believe 
  that 
  it 
  was 
  not 
  without 
  much 
  study 
  that 
  

   I 
  instituted 
  the 
  species 
  now 
  succeeding 
  ; 
  since 
  I 
  did 
  so 
  I 
  have 
  had 
  

   the 
  opportunity, 
  thanks 
  to 
  the 
  kindness 
  of 
  Mr. 
  E. 
  P. 
  Eamsay, 
  of 
  

   examining 
  a 
  collection 
  of 
  Australian 
  Echinodcrms 
  ; 
  and 
  it 
  was 
  ^^'ith 
  

   a 
  certain 
  amount 
  of 
  satisfaction 
  that 
  I 
  obtained 
  from 
  it 
  specimens 
  

   which 
  exhibited 
  a 
  close 
  resemblance 
  to 
  A. 
  intermedia, 
  and 
  led 
  me 
  

   to 
  think 
  that 
  I 
  was 
  justified 
  in 
  -regarding 
  its 
  differential 
  characters 
  

   as 
  constant 
  and 
  definite. 
  

  

  Standing 
  midway 
  between 
  A. 
  soJeiris 
  and 
  A. 
  rohusta 
  it 
  may 
  be 
  

   distinguished 
  as 
  

  

  17. 
  Actinometra 
  intermedia. 
  

  

  As 
  Mr. 
  Carpenter 
  has 
  pointed 
  out, 
  it 
  appears 
  to 
  be 
  possible, 
  in 
  

   part 
  at 
  any 
  rate, 
  to 
  distinguish 
  A. 
  Solaris 
  from 
  A. 
  rohusta 
  by 
  the 
  

   character 
  of 
  the 
  keels, 
  which, 
  in 
  the 
  former, 
  are 
  so 
  strikingly 
  de- 
  

   veloped 
  on 
  the 
  basal 
  joints 
  of 
  the 
  second 
  pinnule. 
  Basing 
  myself 
  on 
  

   the 
  theory 
  that 
  the 
  keel 
  is 
  constantly 
  present 
  on 
  the 
  basal 
  joints 
  of 
  

   the 
  second 
  pinnule 
  of 
  A. 
  Solaris 
  (Plate 
  XVI. 
  fig. 
  A, 
  a), 
  and 
  that 
  it 
  is 
  

   never 
  found 
  on 
  those 
  of 
  A. 
  rohusta 
  (fig. 
  A, 
  h), 
  I 
  venture 
  to 
  think 
  that, 
  

   in 
  the 
  case 
  of 
  A. 
  intermedia, 
  we 
  have 
  to 
  do 
  with 
  a 
  form 
  in 
  which 
  

   constantly 
  the 
  keels 
  are 
  never 
  as 
  well 
  developed 
  as 
  in 
  A. 
  Solaris, 
  

   and 
  never 
  so 
  slightly 
  as 
  in 
  A. 
  rohusta, 
  while 
  at 
  the 
  same 
  time 
  there 
  

   are 
  considerable 
  differences 
  in 
  the 
  extent 
  of 
  the 
  development 
  of 
  the 
  

   keel, 
  not 
  only 
  within 
  the 
  limits 
  of 
  the 
  species 
  but 
  even 
  of 
  the 
  indi- 
  

   vidual 
  (cf. 
  figs. 
  A, 
  c, 
  d). 
  

  

  The 
  following 
  appear 
  to 
  be 
  the 
  more 
  characteristic 
  marks 
  of 
  the 
  

   species 
  : 
  — 
  A 
  general 
  resemblance 
  to 
  A. 
  Solaris 
  ; 
  but 
  there 
  are 
  about 
  

   18 
  cirri, 
  with 
  from 
  18-20 
  joints 
  ; 
  first 
  pinnules 
  not 
  specially 
  long, 
  

   of 
  rather 
  more 
  than 
  40 
  joints 
  ; 
  basal 
  joints 
  of 
  second 
  pinnules 
  

   with 
  a 
  not 
  conspicuous 
  keel, 
  and 
  with 
  one 
  which 
  varies 
  in 
  the 
  

   extent 
  to 
  which 
  it 
  is 
  developed. 
  Arms 
  widest 
  a 
  slight 
  distance 
  

   from 
  the 
  disk. 
  

  

  