﻿lEEDALE 
  & 
  HAT: 
  MISNAMED 
  TASMANIA^ 
  CHITONS. 
  109 
  

  

  broad, 
  covered 
  with 
  regular 
  imbricating 
  small 
  scales 
  ; 
  in 
  the 
  young 
  

   shell 
  these 
  are 
  oval, 
  sub-erect, 
  with 
  ten 
  to 
  twelve 
  deep 
  grooves, 
  the 
  

   apex 
  smooth. 
  Adjacent 
  to 
  the 
  shell 
  these 
  are 
  longer, 
  narrower, 
  and 
  

   more 
  erect. 
  Small 
  squarish 
  granules 
  adorn 
  the 
  edge. 
  In 
  a 
  senile 
  

   shell 
  the 
  scales 
  are 
  all 
  more 
  erect 
  and 
  more 
  deeply 
  grooved, 
  while 
  

   they 
  are 
  more 
  irregular 
  in 
  shape. 
  Length 
  of 
  type 
  (dried 
  shell) 
  

   34 
  mm., 
  breadth 
  18 
  mm. 
  Collected 
  by 
  E. 
  Mawle 
  at 
  Port 
  Arthur, 
  

   South 
  Tasmania. 
  

  

  Kange: 
  south 
  coast 
  of 
  Tasmania. 
  

  

  This 
  distinctive 
  species 
  cannot 
  be 
  confused 
  with 
  any 
  other 
  

   Australian 
  shell, 
  differing 
  as 
  it 
  does 
  in 
  shape, 
  colour, 
  sculpture, 
  and 
  

   internal 
  features. 
  It 
  is 
  a 
  very 
  fine 
  discovery, 
  as 
  it 
  grows 
  to 
  51 
  mm. 
  

   X 
  24 
  mm. 
  in 
  the 
  dried 
  specimen. 
  We 
  have 
  already 
  indicated 
  that 
  

   its 
  relationships 
  are 
  obscure 
  and 
  its 
  range 
  is 
  very 
  restricted 
  so 
  far 
  as 
  

   at 
  present 
  known, 
  for 
  such 
  a 
  conspicuous 
  shell 
  could 
  not 
  escape 
  notice 
  

   by 
  collectors 
  as 
  keen 
  as 
  those 
  of 
  Victoria 
  and 
  South 
  Australia. 
  

  

  11. 
  Chiton 
  divergens, 
  Ileeve. 
  

  

  Reeve's 
  description 
  and 
  figure 
  were 
  not 
  carefully 
  considered" 
  by 
  

   Pilsbry 
  when 
  he 
  separated 
  diverffens, 
  Reeve, 
  from 
  fruticosus, 
  Gould, 
  

   and 
  made 
  Chiton 
  protens, 
  Ileeve, 
  synonymous 
  with 
  the 
  former. 
  

   Pilsbry 
  wrote 
  "Girdle 
  covered 
  with 
  large 
  scales", 
  and 
  remarked, 
  

   **/. 
  divergens 
  has 
  been 
  erroneously 
  united 
  to 
  fruticosus 
  by 
  Angas 
  and 
  

   by 
  Haddon." 
  Angas 
  and 
  Haddon 
  were, 
  however, 
  quite 
  right, 
  as 
  the 
  

   figure 
  shows, 
  and 
  the 
  description 
  " 
  ligament 
  horny, 
  very 
  finely 
  

   granulously 
  coriaceous" 
  is 
  very 
  definite. 
  Reeve's 
  diagnosis 
  of 
  

   Chiton 
  proteus 
  is 
  a 
  perfect 
  description 
  of 
  the 
  shell 
  Pilsbry 
  considered 
  

   *■'■ 
  divergens''\ 
  Tasmanian 
  shells 
  recorded 
  under 
  the 
  latter 
  name 
  do 
  

   not 
  agree 
  with 
  specimens 
  of 
  proteus 
  and 
  are 
  here 
  distinguished. 
  

   AVe 
  may 
  note 
  tliat 
  in 
  the 
  British 
  Museum 
  the 
  shell 
  apparently 
  

   figured 
  by 
  Reeve 
  as 
  C. 
  divergens 
  is 
  on 
  a 
  tablet 
  now 
  labelled 
  fruticosus 
  

   (quite 
  correctly), 
  while 
  the 
  type 
  of 
  proteus 
  appears 
  to 
  be 
  ou 
  a 
  tablet 
  

   labelled 
  " 
  divergens 
  ". 
  

  

  12. 
  IsCHNOCHITON 
  MILLIGANI, 
  n.sp. 
  PI. 
  V, 
  Fig. 
  2. 
  

  

  Shell 
  of 
  full 
  size 
  for 
  the 
  genus, 
  narrowly 
  elongate, 
  not 
  appreciably 
  

   tapering 
  at 
  the 
  ends, 
  elevated, 
  gothic 
  arched, 
  valves 
  not 
  beaked 
  

   nor 
  keeled. 
  Colour 
  varied 
  : 
  greenish 
  of 
  dull 
  shades 
  longitudinally 
  

   streaked 
  with 
  darker. 
  Anterior 
  valve 
  small 
  radially, 
  closely 
  ribbed, 
  

   with 
  numerous 
  low 
  riblets, 
  often 
  divaricating, 
  forty 
  to 
  sixty 
  or 
  more 
  

   according 
  to 
  size. 
  Median 
  valves 
  deep 
  ; 
  lateral 
  areas 
  radially 
  ribbed 
  

   as 
  anterior 
  valve, 
  eight 
  to 
  twelve 
  ribs 
  being 
  counted; 
  ribs 
  low 
  and 
  

   close 
  together. 
  Pleura 
  finely 
  ridged 
  at 
  sides, 
  ridges 
  straight, 
  succeeded 
  

   on 
  jugum 
  by 
  finer 
  sculpture 
  which 
  is 
  sometimes 
  zigzag 
  in 
  character. 
  

   Tail-valve 
  large, 
  mucro 
  elevated 
  at 
  anterior 
  third, 
  posterior 
  slope 
  

   slightly 
  concave 
  ; 
  sculpture 
  of 
  posterior 
  area 
  as 
  of 
  anterior 
  valve 
  and 
  

   anterior 
  portion 
  sculptured 
  as 
  pleural 
  areas. 
  Girdle-scales 
  large, 
  

   oval, 
  and 
  very 
  regular, 
  deeply 
  grooved 
  with 
  eight 
  to 
  ten 
  grooves. 
  

   Interior 
  with 
  red 
  markings, 
  a 
  red 
  horseshoe 
  clearly 
  seen 
  in 
  tail-valve 
  ; 
  

   slitting 
  regularly 
  Ischnoid 
  in 
  character, 
  head-valve 
  in 
  young 
  shell 
  

  

  