﻿IKEDALE 
  & 
  mat: 
  MISNAMED 
  TASMANIAN 
  CHITONS. 
  117 
  

  

  ventured 
  to 
  anticipate. 
  AVe 
  find 
  that 
  not 
  only 
  are 
  the 
  Peronian 
  

   Chitons 
  quite 
  distinct 
  from 
  the 
  Adelaidean 
  ones,but 
  that 
  no 
  Peronian 
  

   species 
  occurs 
  in 
  Tasmania 
  without 
  local 
  variation. 
  Further, 
  that 
  

   a 
  different 
  Chiton 
  fauna 
  is 
  developed 
  in 
  the 
  south 
  and 
  south-east 
  

   bays 
  from 
  that 
  of 
  the 
  north 
  coast. 
  The 
  latter 
  is 
  practically 
  pure 
  

   Adelaidean, 
  but 
  there 
  is 
  a 
  slight 
  Tasmanian 
  element. 
  This 
  Tasmauian 
  

   element 
  is 
  strongly 
  emphasized 
  in 
  the 
  south-east, 
  and 
  shows 
  such 
  

   peculiarities 
  that 
  we 
  propose 
  to 
  designate 
  the 
  east 
  coast 
  of 
  Tasmania, 
  

   the 
  Maugkan 
  Region, 
  and 
  separate 
  it 
  from 
  the 
  Peronian 
  Eegion, 
  

   which 
  we 
  restrict 
  to 
  the 
  east 
  coast 
  of 
  Australia 
  from 
  Bass' 
  Straits 
  to 
  

   Caloundra, 
  Queensland. 
  This 
  nomination 
  will 
  attract 
  zoogeographers, 
  

   and 
  we 
  anticipate 
  confirmation 
  from 
  study 
  in 
  other 
  divisions 
  of 
  

   molluscs, 
  and 
  also 
  other 
  brandies 
  of 
  natural 
  science. 
  As 
  distinctive 
  

   of 
  the 
  Maug6an 
  Region 
  we 
  would 
  cite 
  the 
  species 
  IschnocJiiton 
  mayi, 
  

   Pilsbry, 
  /. 
  {Anisoradsia) 
  mawlei, 
  Heierozona 
  suhviridis, 
  and 
  CaUisto- 
  

   chiton 
  iuaivlei, 
  described 
  in 
  this 
  paper. 
  The 
  genus 
  Eudoxoplax 
  

   has 
  worked 
  into 
  the 
  Adelaidean 
  Region, 
  but 
  not 
  into 
  the 
  Peronian, 
  

   while 
  other 
  genera 
  such 
  as 
  Sypharochton 
  range 
  into 
  the 
  Adelaidean 
  

   only 
  as 
  far 
  as 
  Tasmania 
  is 
  concerned, 
  though 
  otherwise 
  represented 
  

   in 
  the 
  Peronian 
  region. 
  Larger 
  and 
  more 
  extensive 
  collections 
  may 
  

   add 
  further 
  novelties 
  and 
  make 
  the 
  subject 
  more 
  interesting 
  still. 
  

  

  EXPLANATION 
  OF 
  PLATES. 
  

  

  Plate 
  IV. 
  

   Fig. 
  

  

  1. 
  Shell 
  of 
  Chiton 
  lineolatus, 
  'B\a,m\\\\e 
  = 
  contractus, 
  auct., 
  x 
  2, 
  p. 
  108. 
  

   la. 
  Half 
  valve 
  of 
  id., 
  x 
  5, 
  showing 
  sculpture. 
  

  

  2. 
  Shell 
  of 
  Heterozona 
  suhviridis, 
  n.sp., 
  x 
  2, 
  p. 
  105. 
  

   2a. 
  Section 
  of 
  girdle 
  of 
  id., 
  x 
  7. 
  

  

  3. 
  Shell 
  of 
  Ischnochiton 
  atkinsoni, 
  n.sp., 
  x 
  8, 
  p. 
  110. 
  

   3a. 
  Half 
  valve 
  of 
  id., 
  x 
  12, 
  showing 
  sculpture. 
  

  

  3a". 
  Section 
  of 
  girdle 
  of 
  id., 
  x 
  24. 
  

  

  3a'". 
  Section 
  of 
  girdle 
  of 
  I. 
  decoratus, 
  Sykes, 
  x 
  24. 
  

  

  4. 
  Shell 
  of 
  I. 
  (Anisoradsia) 
  maivlei, 
  n.sp., 
  x 
  2, 
  p. 
  108. 
  

  

  5. 
  Shell 
  of 
  Callistochiton 
  mawlei, 
  n.sp., 
  x 
  4, 
  p. 
  113. 
  

  

  5a. 
  Half 
  valve 
  of 
  id., 
  to 
  show 
  sculpture 
  and 
  sutural 
  plate, 
  x 
  8. 
  

   5a'. 
  Half 
  valve 
  of 
  C. 
  antiquus, 
  Reeve, 
  from 
  Caloundra, 
  Queensland, 
  x 
  10, 
  

   for 
  comparison. 
  

  

  Plate 
  V. 
  

  

  1. 
  ^heW 
  oi 
  Rhyssoplax 
  diapliora, 
  n.sT^., 
  x 
  2, 
  p. 
  115. 
  

   la. 
  Section 
  through 
  pleural 
  area 
  of 
  half 
  valve 
  of 
  id., 
  x 
  4. 
  

  

  la". 
  Section 
  through 
  pleural 
  area 
  of 
  half 
  valve 
  of 
  R. 
  jugosa, 
  x 
  4. 
  

  

  2. 
  Shell 
  oi 
  Ischnochiton 
  miliigani, 
  n.sp., 
  x 
  2, 
  p. 
  109. 
  

   2a". 
  Half 
  valve 
  of 
  id., 
  x 
  5. 
  

  

  2a"'. 
  Half 
  valve 
  of 
  J. 
  proteiis, 
  for 
  comparison, 
  x 
  5. 
  

  

  3. 
  Shell 
  of 
  I. 
  torri, 
  n.sp., 
  x 
  2, 
  p. 
  111. 
  

   3a. 
  Section 
  of 
  girdle 
  of 
  id., 
  x 
  50. 
  

  

  3a". 
  Section 
  of 
  girdle 
  of 
  Chiton 
  ustulatus, 
  Reeve, 
  x 
  50. 
  

  

  4. 
  Shell 
  of 
  Tasmanian 
  specimen 
  of 
  PZaxip/ioraTOaWTiewsi, 
  Iredale, 
  x 
  2J, 
  p. 
  101. 
  

   4a. 
  Tail-valve 
  of 
  id., 
  side 
  view. 
  

  

  4a'. 
  Tail-valve 
  of 
  id., 
  front 
  view. 
  

  

  5. 
  ^heWoi 
  Sypharochitonmaugeanus,n.ST^., 
  x 
  f 
  , 
  p. 
  114. 
  

  

  *^^* 
  The 
  enlargements 
  are 
  only 
  approximate. 
  

   VOL. 
  XII. 
  — 
  NOV. 
  1916. 
  9 
  

  

  