﻿NEWTON: 
  ON 
  ATUBIA 
  ATUBI. 
  163 
  

  

  conceuti-ically 
  laminate 
  structure. 
  On 
  account 
  of 
  its 
  shape 
  and 
  

   position, 
  there 
  is 
  also 
  the 
  suggestion 
  that 
  this 
  supposed 
  valve 
  may 
  

   be 
  the 
  remnants 
  of 
  the 
  hood 
  of 
  the 
  Cephalopod, 
  whicli, 
  according 
  

   to 
  Owen' 
  with 
  regard 
  to 
  Nautilus, 
  is 
  a 
  " 
  ligamento-muscular 
  disc 
  

   that 
  surmounts 
  the 
  head". 
  This 
  Nautiloid 
  was 
  long 
  considered 
  to 
  

   belong 
  to 
  Aturia 
  %iczac 
  (Sowerby) 
  of 
  Eocene 
  times, 
  although, 
  as 
  

   pointed 
  out 
  by 
  J)r. 
  Foord 
  and 
  other 
  palceontologists, 
  the 
  two 
  species 
  

   are 
  quite 
  distinct, 
  Aturia 
  aturi 
  ht^iw^ 
  a 
  much 
  more 
  compressed 
  shell 
  

   and 
  possessing 
  a 
  more 
  elongate 
  aperture. 
  

  

  Bimemions 
  of 
  specimen 
  ; 
  — 
  mm. 
  

  

  Height 
  (total) 
  182 
  (= 
  TiVi"-)- 
  

  

  Width 
  of 
  body-whorl 
  (maximum) 
  . 
  118 
  

  

  Width 
  from 
  iimbilicus 
  to 
  periphery 
  . 
  93 
  

  

  Depth 
  near 
  septal 
  region 
  ... 
  40 
  

  

  Maximum 
  width 
  of 
  aperture 
  (approximate) 
  55 
  

  

  History 
  and 
  SruATiGiiArm' 
  of 
  the 
  Species. 
  

  

  Messrs. 
  Jutson 
  and 
  Simpson 
  may 
  claim 
  to 
  have 
  first 
  recorded 
  this 
  

   fossil 
  from 
  Western 
  Australia, 
  and 
  determined 
  it 
  as 
  Aturia 
  australis 
  

   in 
  1915. 
  They 
  obtained 
  it 
  from 
  the 
  north-east 
  of 
  Albany, 
  where 
  

   probably 
  Mr. 
  Field's 
  specimen 
  was 
  found, 
  in 
  " 
  marine 
  beds 
  forming 
  

   a 
  low 
  plateau 
  " 
  which 
  they 
  termi 
  d 
  the 
  " 
  Plantagenet 
  Beds 
  " 
  ; 
  it 
  was 
  

   associated 
  with 
  Mollusca, 
  Bryozoa, 
  Echinoids, 
  and 
  an 
  abundance 
  

   of 
  siliceous 
  Sponges.- 
  No 
  figure 
  or 
  description 
  -was 
  given 
  of 
  their 
  

   specimen, 
  although 
  the 
  authors 
  mentioned 
  that 
  the 
  species 
  was 
  

   known 
  in 
  the 
  Tertiaries 
  of 
  Victoria, 
  wh<!re 
  it 
  extended 
  from 
  the 
  

   Oligocene 
  to 
  the 
  Pliocene 
  formations. 
  This 
  is 
  probably 
  the 
  first 
  

   reliable 
  determination 
  of 
  a 
  Tertiary 
  mollusc 
  from 
  Western 
  Australia, 
  

   their 
  usually 
  imperfect 
  preservation 
  liaving 
  hitherto 
  militated 
  

   against 
  the 
  compilation 
  of 
  accurate 
  specific 
  lists 
  from 
  wliicli 
  to 
  obtain 
  

   a 
  knowledge 
  of 
  fannistic 
  assemblages, 
  a 
  fact 
  which 
  has 
  been 
  

   I'emarked 
  upon 
  by 
  Mr. 
  1>. 
  Glauert 
  ^ 
  as 
  late 
  as 
  1910. 
  In 
  this 
  way 
  

   they 
  form 
  a 
  striking 
  contrast 
  to 
  fossils 
  found 
  in 
  the 
  Victorian 
  and 
  

   South 
  Australian 
  Tertiaries, 
  which 
  are 
  of 
  prolific 
  occurrence 
  and 
  

   usually 
  in 
  a 
  fine 
  state 
  of 
  preservation. 
  The 
  presence 
  of 
  this 
  

   organism 
  in 
  Australian 
  rocks 
  was, 
  however, 
  fiist 
  indicated 
  by 
  J. 
  E. 
  

   Tenison-Woods, 
  whose 
  brief 
  description 
  of 
  the 
  same 
  was 
  accompanied 
  

   by 
  an 
  excellent 
  text-figure 
  of 
  a 
  cast 
  showing 
  tlie 
  septal 
  region, 
  but 
  

   with 
  no 
  body-whorl. 
  It 
  was 
  referred 
  to 
  as 
  the 
  most 
  predominant 
  

   fossil 
  of 
  the 
  Mount 
  Gambier 
  beds 
  of 
  South 
  Australia, 
  although 
  its 
  

   determination 
  was 
  mistaken 
  for 
  Nautilus 
  ziczac 
  of 
  J. 
  Sowerby, 
  

  

  ' 
  Richard 
  Owen, 
  Memoir 
  on 
  the 
  Pearly 
  Naihilus, 
  1832, 
  pp. 
  11, 
  12, 
  pi. 
  i, 
  

   fig. 
  n; 
  pi. 
  ii, 
  fig. 
  h. 
  

  

  " 
  These 
  sponges 
  are 
  probably 
  similar 
  to 
  those 
  found 
  at 
  Norseman 
  in 
  Western 
  

   Australia, 
  described 
  by 
  Dr. 
  Hinde 
  (Bull. 
  Geol. 
  Surv. 
  W. 
  Australia, 
  

   1910, 
  No. 
  36, 
  pp. 
  7-21, 
  pis. 
  i-iii), 
  which 
  Mr. 
  Chapman 
  considers, 
  " 
  in 
  

   some 
  respects," 
  to 
  resemble 
  the 
  spicule-bearing 
  rock 
  of 
  Oamaru 
  in 
  New 
  

   Zealand, 
  which 
  is 
  of 
  Miocene 
  age 
  {Australasian 
  Fossils, 
  1914, 
  p. 
  110). 
  

  

  3 
  Bull. 
  36, 
  Geol, 
  Surv, 
  W. 
  Australia, 
  1910, 
  p. 
  71. 
  

  

  