﻿IKED 
  ALE 
  : 
  NOTES 
  ON 
  POLTPLACOPHOEA. 
  161 
  

  

  each 
  other, 
  and 
  from 
  the 
  Eudoxochitons 
  of 
  New 
  Zealand. 
  A 
  species 
  

   of 
  Plaxiphora 
  was 
  obtained 
  which 
  agrees 
  with 
  the 
  New 
  Zealand 
  

   c(Blata, 
  Keeve, 
  in 
  everything 
  save 
  girdle-characters. 
  It 
  has 
  the 
  girdle 
  

   densely 
  crowded 
  with 
  hairs 
  instead 
  of 
  with 
  few 
  hairs, 
  as 
  in 
  that 
  

   species. 
  All 
  the 
  specimens 
  collected 
  agreed 
  in 
  this 
  respect. 
  A 
  beautiful 
  

   smooth 
  Onithochiton 
  in 
  the 
  characters 
  of 
  the 
  valves, 
  externally 
  and 
  

   internally, 
  cannot 
  be 
  separated 
  from 
  smooth 
  undulahifi, 
  Q. 
  & 
  G. 
  

   But 
  its 
  girdle 
  is 
  clothed 
  with 
  slender 
  glassy 
  spikes 
  like 
  that 
  of 
  

   Onithochiton 
  amicorum, 
  Baird, 
  from 
  Nine. 
  I 
  have 
  examined 
  the 
  type 
  

   of 
  this 
  species, 
  and 
  though 
  it 
  is 
  in 
  bad 
  condition 
  it 
  is 
  certainly 
  an 
  

   Onithochiton. 
  A 
  Chiton 
  was 
  procured 
  which 
  had 
  developed 
  most 
  

   peculiar 
  habits 
  : 
  it 
  lived 
  in 
  crevices 
  of 
  rock 
  between 
  tide-marks, 
  

   huddling 
  together, 
  half 
  a 
  dozen 
  being 
  found 
  one 
  upon 
  another, 
  so 
  that 
  

   some 
  did 
  not 
  touch 
  the 
  rock 
  at 
  all. 
  This 
  species 
  was 
  entirely 
  black, 
  

   and 
  allied 
  to 
  pellis-serpentis, 
  Q. 
  & 
  G. 
  A 
  small 
  Lepidopleurus 
  was 
  

   living 
  under 
  dirty 
  stones 
  below 
  low-water. 
  It 
  was 
  only 
  on 
  the 
  under- 
  

   side 
  of 
  stones 
  deeply 
  embedded. 
  On 
  smooth 
  stones 
  just 
  below 
  low- 
  

   water 
  lived 
  species 
  of 
  Chiton, 
  of 
  the 
  <zreus, 
  Reeve, 
  group, 
  and 
  

   Ischnochiion, 
  of 
  the 
  crispus, 
  Reeve, 
  group. 
  I 
  have 
  written 
  species, 
  

   as 
  I 
  have 
  so 
  far 
  failed 
  to 
  realize 
  how 
  many 
  or 
  how 
  few 
  I 
  have 
  

   collected. 
  The 
  shells 
  can 
  be 
  separated 
  into 
  three 
  forms 
  of 
  Chiton 
  and 
  

   two 
  of 
  Tschnochiton, 
  but 
  I 
  am 
  almost 
  in 
  the 
  position 
  of 
  the 
  ornithologist 
  

   who 
  could 
  see 
  the 
  differences 
  but 
  could 
  not 
  write 
  them 
  down. 
  If 
  these 
  

   forms 
  could 
  be 
  classed 
  as 
  variations 
  of 
  one 
  species 
  of 
  each 
  genus, 
  that 
  

   would 
  seem 
  best, 
  but 
  then 
  we 
  are 
  confronted 
  with 
  the 
  facts 
  that 
  

   C. 
  cereus, 
  Reeve, 
  and 
  its 
  relations 
  are 
  very 
  constant, 
  as 
  also 
  is 
  

   I. 
  crispus, 
  Reeve. 
  Then 
  how 
  should 
  a 
  species 
  of 
  such 
  groups 
  

   commence 
  varying 
  under 
  such 
  restricted 
  conditions 
  as 
  is 
  offered 
  them 
  

   on 
  such 
  a 
  small 
  area 
  ? 
  These 
  forms 
  were 
  all 
  living 
  under 
  absolutely 
  

   the 
  same 
  conditions, 
  so 
  that 
  I 
  have 
  been 
  forced 
  to 
  suggest 
  that 
  they 
  

   present 
  convergence 
  of 
  species 
  through 
  the 
  action 
  of 
  identical 
  external 
  

   conditions. 
  From 
  15 
  to 
  25 
  fathoms 
  was 
  dredged 
  a 
  fine 
  Lepidopleurus, 
  

   which 
  has 
  no 
  near 
  relation 
  yet 
  on 
  record. 
  It 
  faintly 
  resembles 
  some 
  

   Japanese 
  species. 
  From 
  a 
  piece 
  of 
  coral 
  pulled 
  out 
  of 
  6 
  feet 
  of 
  

   water 
  at 
  low 
  tide 
  a 
  small 
  Tonicia 
  was 
  detached, 
  whose 
  affinities 
  are 
  

   Polynesian. 
  As 
  valves 
  of 
  similar 
  size 
  were 
  common 
  in 
  dredgings, 
  it 
  

   would 
  appear 
  to 
  be 
  adult. 
  Associated 
  with 
  these 
  were 
  valves 
  of 
  

   two 
  small 
  species 
  of 
  Acanthochites, 
  a 
  genus 
  not 
  otherwise 
  met 
  with. 
  

   That 
  the 
  Chitons 
  were 
  not 
  completely 
  collected 
  was 
  evidenced 
  by 
  

   finding 
  a 
  valve 
  of 
  a 
  large 
  Chiton, 
  apparently 
  a 
  Cryptoconchus, 
  in 
  shell- 
  

   sand 
  on 
  an 
  exposed 
  piece 
  of 
  the 
  coast. 
  "When 
  the 
  Chitons 
  of 
  New 
  

   Caledonia 
  are 
  more 
  fully 
  known 
  than 
  at 
  present, 
  I 
  believe 
  they 
  will 
  

   show 
  near 
  relationship 
  to 
  those 
  of 
  New 
  Zealand. 
  "When 
  Suter 
  

   described 
  Chiton 
  Huttoni 
  (T.N.Z.I., 
  vol. 
  xxxviii, 
  p. 
  329, 
  1905 
  (06)), 
  

   he 
  remarked, 
  "the 
  affinities 
  of 
  the 
  marine 
  molluscs 
  of 
  New 
  Caledonia 
  

   and 
  New 
  Zealand 
  are 
  slender." 
  But 
  that 
  species 
  and 
  C. 
  m-eus, 
  Reeve, 
  

   have 
  a 
  very 
  close 
  ally 
  in 
  the 
  New 
  Caledonian 
  C. 
  discolor, 
  Souverbie 
  

   { 
  = 
  minaceus, 
  Cpr. 
  MSS., 
  and 
  perpunctatus, 
  Cpr. 
  MSS.) 
  ; 
  and 
  the 
  more 
  

   recently 
  described 
  Chiton 
  clavatus, 
  Suter 
  (Proc. 
  Malac. 
  Soc, 
  vol. 
  vii, 
  

   p. 
  296, 
  fig. 
  3, 
  1907), 
  from 
  New 
  Zealand, 
  seems 
  very 
  near 
  Chiton 
  

  

  