﻿CRUSTACEA. 
  297 
  

  

  peduncles 
  of 
  the 
  antennje 
  are 
  very 
  short, 
  completely 
  concealed 
  

   beneath 
  the 
  large 
  basal 
  scales, 
  which 
  reach 
  slightly 
  beyond 
  the 
  an- 
  

   tennal 
  peduncles, 
  narrow 
  to 
  their 
  apices, 
  and 
  have 
  a 
  small 
  spinvde 
  

   at 
  the 
  distal 
  ends 
  of 
  their 
  outer 
  margins. 
  The 
  outer 
  maxillipedes 
  

   are 
  rather 
  robust 
  and 
  elongated, 
  reaching, 
  when 
  thrown 
  forward, 
  

   almost 
  to 
  the 
  apices 
  of 
  the 
  antennal 
  scales. 
  The 
  first 
  legs 
  are 
  much 
  

   shorter 
  than 
  the 
  following, 
  with 
  the 
  joints 
  compressed, 
  the 
  dactyli 
  

   acute, 
  and 
  the 
  basus 
  and 
  ischium-joints 
  have 
  each 
  a 
  small 
  spine 
  at 
  

   the 
  distal 
  ends 
  of 
  their 
  inner 
  margins 
  ; 
  the 
  second 
  and 
  third 
  cheli- 
  

   pedes 
  are 
  slender 
  (the 
  hasus-joint 
  of 
  the 
  second 
  legs 
  bears 
  a 
  small 
  

   spine) 
  ; 
  the 
  third 
  are 
  longer 
  than 
  the 
  second 
  ; 
  the 
  fourth 
  legs 
  are 
  

   slender 
  and 
  rarely 
  as 
  long 
  as 
  the 
  third 
  ; 
  the 
  fifth 
  are 
  imperfect. 
  

   The 
  rami 
  of 
  the 
  iiropoda 
  are 
  narrow, 
  and 
  reach 
  about 
  to 
  the 
  end 
  of 
  

   the 
  terminal 
  segment 
  ; 
  the 
  outer 
  has 
  the 
  lateral 
  margins 
  nearly 
  

   parallel 
  ; 
  in 
  the 
  inner 
  ramus 
  they 
  converge 
  very 
  slightly 
  to 
  the 
  

   rounded 
  extremity. 
  Colour 
  (in 
  spirit) 
  purplish 
  beneath 
  the 
  cinereous 
  

   pubescence. 
  Length 
  about 
  2 
  inches 
  10 
  lines 
  (72 
  millim.). 
  

  

  The 
  unique 
  example 
  (a 
  female) 
  was 
  obtained 
  at 
  Albany 
  Island 
  in 
  

   3-4 
  fms. 
  

  

  The 
  palpi 
  of 
  the 
  mandibles 
  are 
  two-jointed 
  ; 
  the 
  joints 
  flattened, 
  

   dilated, 
  and 
  ciliated, 
  as 
  in 
  Pencms. 
  

  

  As 
  the 
  specimen 
  is 
  unique, 
  I 
  have 
  not 
  been 
  able 
  to 
  make 
  a 
  com- 
  

   plete 
  examination 
  of 
  the 
  branchiae 
  ; 
  but 
  I 
  think 
  (as 
  in 
  the 
  true 
  

   Fencei 
  as 
  restricted 
  by 
  Mr. 
  Hpence 
  Bate) 
  no 
  true 
  podobranchiae 
  are 
  

   present, 
  but 
  merely 
  the 
  epipoditic 
  appendages 
  or 
  " 
  mastibranchise 
  " 
  

   as 
  he 
  denominates 
  them 
  *. 
  

  

  There 
  are, 
  besides, 
  in 
  the 
  collection 
  from 
  Port 
  Denison 
  a 
  speci- 
  

   men 
  closely 
  allied 
  to 
  Pasipluva 
  and 
  to 
  LeptocJula, 
  Stimpson 
  ; 
  and 
  

   another 
  crustacean, 
  perhaps 
  belonging 
  to 
  the 
  Pena^idea, 
  which, 
  being 
  

   in 
  very 
  mutilated 
  condition, 
  cannot 
  be 
  described 
  in 
  detail, 
  and 
  

   which 
  I 
  leave 
  for 
  the 
  present 
  iindetermined, 
  

  

  * 
  Vide 
  Spence 
  Bate 
  " 
  On 
  the 
  Peufcidea," 
  Aim. 
  & 
  Mag. 
  Nat. 
  Hist. 
  ser. 
  5, 
  viii. 
  

   p. 
  174(1881). 
  

  

  In 
  this 
  recent 
  memoir 
  on 
  the 
  Penseidea 
  several 
  new 
  genera 
  and 
  not 
  a 
  

   few 
  new 
  species 
  have 
  been 
  very 
  briefly 
  characterized, 
  to 
  none 
  of 
  which, 
  I 
  

   believe, 
  can 
  our 
  new 
  form 
  be 
  referred. 
  The 
  descriptions, 
  however, 
  are 
  in- 
  

   sufBcient. 
  From 
  HemvpencBus, 
  which 
  this 
  species 
  resembles 
  in 
  its 
  short 
  and 
  few- 
  

   toothed 
  rostrum, 
  it 
  differs 
  in 
  the 
  structure 
  of 
  the 
  flagella 
  of 
  the 
  antennules. 
  

  

  Mr. 
  Spence 
  Bate 
  includes 
  in 
  the 
  very 
  insufficiently 
  defined 
  genus 
  PencBopsis 
  the 
  

   P. 
  styliferus, 
  M.-Edwards, 
  with 
  which 
  he 
  apparently 
  considers 
  P. 
  dohsoni, 
  Miers, 
  

   to 
  be 
  identical. 
  He 
  has 
  strangely 
  overlooked 
  an 
  important 
  distinction, 
  twice 
  

   mentioned 
  by 
  me 
  in 
  my 
  paper 
  {vide 
  Proc. 
  Zool. 
  See. 
  1878, 
  pp. 
  305, 
  307), 
  

   namely 
  the 
  absence 
  of 
  lateral 
  marginal 
  spinnles 
  on 
  the 
  terminal 
  postabdorainal 
  

   segment. 
  They 
  are 
  absent, 
  I 
  may 
  add, 
  alike 
  in 
  the 
  female 
  and 
  in 
  Prof. 
  

   Wood-Mason's 
  small 
  male. 
  The 
  existence 
  of 
  these 
  in 
  P. 
  styliferus 
  is 
  mentioned 
  

   by 
  Milne-Edwards 
  in 
  his 
  original 
  description 
  of 
  that 
  species, 
  and 
  tliey 
  are 
  

   present 
  also 
  in 
  a 
  specimen 
  referred 
  to 
  P. 
  styliferus 
  in 
  the 
  British-Museum 
  

   collection. 
  

  

  