﻿CRUSTACEA. 
  301 
  

  

  already 
  given 
  of 
  it 
  in 
  the 
  ' 
  Catalogue 
  of 
  New-Zealand 
  Crustacea' 
  

   will 
  apply 
  equally 
  well 
  to 
  the 
  smaller 
  Australian 
  examples, 
  except 
  

   that 
  iu 
  these 
  latter 
  the 
  eyes 
  are 
  distinct 
  and 
  dark-coloured, 
  the 
  

   antero-lateral 
  prolongations 
  of 
  the 
  first 
  thoracic 
  segment 
  (in 
  the 
  

   smallest 
  specimen 
  especially) 
  somewhat 
  narrower 
  at 
  base, 
  and 
  the 
  

   posterior 
  margin 
  of 
  the 
  terminal 
  postabdominal 
  segment 
  somewhat 
  

   arcuated*. 
  

  

  The 
  type 
  of 
  Fabricius's 
  Cymotlioa 
  imhricata 
  is 
  also 
  in 
  the 
  British- 
  

   Museum 
  collection 
  (from 
  the 
  collection 
  of 
  Sir 
  J. 
  Banks), 
  and 
  I 
  am 
  

   enabled 
  to 
  identify 
  Leach's 
  species 
  with 
  it 
  with 
  tolerable 
  certainty. 
  

   The 
  slight 
  notch 
  in 
  the 
  terminal 
  segment 
  mentioned 
  by 
  Fal)ricius 
  is, 
  

   I 
  think, 
  merely 
  due 
  to 
  an 
  accident. 
  As 
  White 
  referred 
  Fabricius's 
  

   Ci/mothoa 
  imhricata 
  to 
  the 
  genus 
  Nerocila, 
  and 
  the 
  type, 
  when 
  my 
  

   New-Zealand 
  Catalogue 
  was 
  published, 
  had 
  not 
  been 
  placed 
  in 
  the 
  

   general 
  collection 
  of 
  the 
  Museum, 
  I 
  did 
  not 
  then 
  suspect 
  its 
  identity 
  

   with 
  C. 
  hanhsii. 
  The 
  species 
  in 
  the 
  New-Zealand 
  Catalogue 
  (p. 
  107) 
  

   which 
  I 
  designated, 
  after 
  White, 
  Nerocila 
  imhricata 
  must 
  be 
  called 
  

   Nerocila 
  madeai/ii, 
  White 
  having 
  previously 
  nsed 
  this 
  name 
  for 
  it 
  

   (vide 
  Dieffenb. 
  Voy. 
  New 
  Zealand, 
  ii. 
  p. 
  268, 
  1813). 
  

  

  It 
  is 
  not 
  improbable 
  that 
  the 
  original 
  C. 
  trigonocepluda. 
  Leach, 
  

   must 
  also 
  be 
  regarded 
  as 
  synonymous 
  with 
  this 
  species 
  ; 
  neverthe- 
  

   less, 
  as 
  the 
  type 
  specimens 
  (which 
  are 
  dried 
  and 
  without 
  definite 
  

   locality) 
  present 
  certain 
  slight 
  distinctive 
  characters, 
  as 
  {e. 
  g.) 
  the 
  

   head 
  is 
  narrower, 
  more 
  distinctly 
  triangulate, 
  with 
  straight 
  sides, 
  

   and 
  the 
  anterior 
  thoracic 
  segment 
  proportionately 
  longer 
  than 
  is 
  

   usual 
  in 
  C. 
  imhricata, 
  I 
  keep 
  tliem 
  provisionally 
  distinct 
  {cf. 
  Ann. 
  

   & 
  Mag. 
  Nat. 
  Hist. 
  ser. 
  5, 
  v. 
  p. 
  4(33, 
  1880). 
  To 
  ascertain 
  the 
  true 
  

   distinctive 
  characters 
  of 
  the 
  species 
  of 
  this 
  difiicult 
  group, 
  a 
  careful 
  

   revision 
  of 
  the 
  whole 
  subject 
  is 
  needed. 
  Milne-Edwards's 
  descrip- 
  

   tion 
  of 
  C. 
  tri(jonocephala 
  in 
  the 
  ' 
  Histoire 
  natureUe 
  des 
  Crustaces 
  ' 
  

   seems 
  to 
  have 
  been 
  drawn 
  up 
  from 
  specimens 
  of 
  a 
  variety 
  having 
  a 
  

   more 
  obtuse 
  front, 
  and 
  the 
  anterior 
  margin 
  of 
  the 
  first 
  thoracic 
  seg- 
  

   ment 
  armed 
  with 
  a 
  median 
  lobe 
  or 
  tooth. 
  Specimens 
  presenting 
  

   these 
  characters 
  are 
  in 
  the 
  British-Museum 
  collection 
  from 
  Shark 
  

   Bay. 
  Mr. 
  Haswell, 
  in 
  his 
  Catalogue, 
  and 
  Thomson 
  (t. 
  c.) 
  merely 
  

   copy 
  ]k[.-Edwards's 
  description. 
  

  

  I 
  refer 
  specimens 
  in 
  the 
  Museum 
  collection 
  to 
  Ceratotlioa 
  imhri- 
  

   cata 
  from 
  Port 
  Essington 
  (Haslar 
  Hospital) 
  ; 
  Sydney, 
  Murray 
  River 
  

   {A. 
  E. 
  Craven, 
  from 
  the 
  mouth 
  of 
  a 
  salmon-trout) 
  ; 
  Shark 
  Bay, 
  W. 
  

   Australia 
  (from 
  a 
  species 
  of 
  Monacanthus) 
  ; 
  Calcutta 
  (designated 
  by 
  

   White 
  C. 
  approximans) 
  ; 
  and 
  various 
  other 
  specimens 
  without 
  special 
  

   indication 
  of 
  locality. 
  

  

  3. 
  Cirolana 
  multidigitata, 
  Dana. 
  

  

  A 
  small 
  female 
  from 
  Albany 
  Island 
  belongs, 
  I 
  think, 
  to 
  this 
  

   species. 
  

  

  * 
  The 
  posterior 
  margin 
  in 
  Leach's 
  typo 
  is 
  sliglitij 
  rolled 
  in 
  througli 
  the 
  desic- 
  

   cation 
  of 
  the 
  specimen 
  ; 
  it 
  should 
  not 
  have 
  been 
  described 
  as 
  " 
  nearly 
  straight." 
  

  

  