﻿CRUSTACEA. 
  251 
  

  

  The 
  larger 
  specimen 
  closely 
  resembles 
  the 
  specimens 
  referred 
  to 
  

   M. 
  affinis 
  in 
  the 
  Museum 
  collection, 
  and 
  scarcely 
  differs 
  from 
  M. 
  mam- 
  

   millaris 
  except 
  in 
  the 
  (relatively) 
  somewhat 
  longer, 
  more 
  acute 
  

   median 
  spine 
  of 
  the 
  posterior 
  margin, 
  and 
  shorter 
  chelipedes 
  ; 
  and 
  I 
  

   think 
  it 
  probable 
  that 
  a 
  larger 
  series 
  would 
  demonstrate 
  the 
  necessity 
  

   of 
  uniting 
  the 
  two 
  species. 
  The 
  younger 
  examples 
  may 
  be 
  distin- 
  

   guished 
  from 
  those 
  referred 
  to 
  iM. 
  australis 
  by 
  their 
  narrower 
  cara- 
  

   pace, 
  and 
  the 
  longer, 
  more 
  acute, 
  and 
  non-recurved 
  posterior 
  marginal 
  

   spines. 
  

  

  100. 
  Myra 
  mammillaris, 
  Bell. 
  

  

  An 
  adult 
  male 
  is 
  in 
  the 
  collection 
  from 
  Port 
  Denison, 
  4 
  fms. 
  

   (?^o. 
  111). 
  

  

  There 
  are 
  in 
  the 
  Museum 
  collection 
  specimens 
  from 
  Adelaide, 
  

   S. 
  Austraha 
  (purchased), 
  and 
  others 
  without 
  special 
  locality. 
  

  

  101. 
  Myra 
  australis, 
  i/asweZ/ 
  ? 
  

  

  Mvra 
  mammillaris 
  (young), 
  Miers, 
  Trans. 
  Linn. 
  Soc. 
  ser 
  2, 
  Zool. 
  i. 
  

  

  p. 
  239, 
  pi. 
  xxxviii. 
  tigs. 
  25-27 
  (1877). 
  

   ? 
  Myra 
  australis, 
  Hasioell, 
  Proc. 
  Linn. 
  Soc. 
  N. 
  S. 
  W. 
  iv. 
  p. 
  50, 
  pi. 
  v. 
  

  

  fig. 
  3 
  (1880); 
  Catalixjve, 
  p. 
  122 
  (1882). 
  

  

  Three 
  specimens 
  are 
  referred 
  doubtfuUy 
  to 
  this 
  form 
  from 
  Port 
  

   Molle, 
  14 
  fms. 
  (No. 
  93), 
  and 
  one 
  from 
  Port 
  Denison, 
  4 
  fms. 
  (No. 
  122) 
  

   (first 
  collection) 
  ; 
  also 
  a 
  male 
  from 
  Thursday 
  Island, 
  3-4 
  fms. 
  

   (No. 
  177), 
  two 
  females 
  from 
  the 
  same 
  locality, 
  4-5 
  fms, 
  (No. 
  165), 
  

   (to 
  the 
  back 
  of 
  one 
  of 
  which 
  is 
  attached 
  a 
  fine 
  specimen 
  of 
  a 
  species 
  

   of 
  Acetabularia), 
  and 
  two 
  males 
  from 
  Prince 
  of 
  Wales 
  Channel, 
  

   obtained 
  at 
  7 
  fms. 
  (No. 
  142) 
  and 
  9 
  fms. 
  (No. 
  157). 
  

  

  In 
  some 
  of 
  the 
  specimens 
  I 
  have 
  examined 
  the 
  carapace 
  is 
  much 
  

   more 
  evenly 
  granulated 
  than 
  in 
  others, 
  and 
  they 
  also 
  differ 
  in 
  the 
  

   more 
  or 
  less 
  recurved 
  posterior 
  median 
  spine 
  and 
  the 
  greater 
  or 
  

   lesser 
  dilatation 
  of 
  the 
  intestinal 
  region 
  ; 
  in 
  some 
  females 
  the 
  post- 
  

   abdomen 
  is 
  comparatively 
  narrow, 
  whereas 
  in 
  others 
  it 
  covers 
  the 
  

   whole 
  of 
  the 
  sternal 
  surface. 
  Although 
  some 
  of 
  the 
  larger 
  spe- 
  

   cimens 
  approach 
  nearly 
  in 
  their 
  characters 
  to 
  31. 
  mammillaris, 
  yet, 
  

   as 
  all 
  may 
  be 
  distinguished 
  by 
  their 
  more 
  orbiculate 
  carapace, 
  more 
  

   acutely-angulated 
  pterygostomian 
  regions, 
  the 
  more 
  or 
  less 
  recurved 
  

   posterior 
  median 
  spine, 
  and 
  relatively 
  shorter 
  chelipedes, 
  I 
  prefer 
  to 
  

   adopt 
  for 
  them, 
  at 
  least 
  provisionally, 
  Mr. 
  Haswell's 
  specific 
  name. 
  

   I 
  should 
  add, 
  however, 
  that 
  in 
  Mr. 
  Haswell's 
  figure 
  the 
  male 
  post- 
  

   abdomen 
  is 
  represented 
  as 
  shorter 
  than 
  in 
  our 
  specimens, 
  with 
  the 
  

   sides 
  somewhat 
  constricted 
  at 
  base 
  of 
  the 
  terminal 
  segment. 
  

  

  There 
  are 
  specimens 
  from 
  Shark 
  Pay, 
  West 
  Australia, 
  in 
  the 
  

   Museum 
  collection 
  (H.M.S. 
  "■ 
  Hera 
  Id') 
  which 
  probably 
  belong 
  here, 
  

   but 
  in 
  one 
  (a 
  female) 
  the 
  granulations 
  of 
  the 
  carapace 
  are 
  very 
  

   indistinct. 
  

  

  