﻿CRUSTACEA. 
  281 
  

  

  0. 
  carinicauda 
  is 
  nearly 
  allied 
  to, 
  and 
  may 
  prove 
  to 
  be 
  identical 
  

   with, 
  O. 
  Urtifrons, 
  White, 
  which 
  Mr. 
  Haswell 
  (Cat. 
  p. 
  164) 
  men- 
  

   tions 
  as 
  commonly 
  occurring 
  in 
  sponges 
  at 
  Port 
  Jackson 
  ; 
  but 
  in 
  tho 
  

   latter 
  species 
  the 
  spine 
  of 
  the 
  lower 
  margin 
  of 
  the 
  hand 
  (which 
  exists 
  

   in 
  adult 
  examples 
  of 
  O. 
  carinicauda) 
  is 
  absent. 
  I 
  may 
  add 
  that 
  in 
  

   the 
  type 
  specimen 
  of 
  0. 
  hirtifrons 
  the 
  bases 
  of 
  the 
  second, 
  as 
  well 
  as 
  

   of 
  the 
  third, 
  pair 
  of 
  legs 
  bear 
  a 
  spiuule. 
  

  

  2. 
  Gebiopsis 
  darwinii. 
  (Plate 
  XXXII. 
  fig. 
  A.) 
  

  

  The 
  carapace 
  is 
  vertically 
  deep 
  and 
  laterally 
  compressed 
  (as 
  in 
  

   Qehiopsis 
  nitidus, 
  A. 
  M.-Edw.) 
  ; 
  its 
  sides 
  converge 
  very 
  slightly 
  to 
  

   the 
  front, 
  which 
  has 
  four 
  median 
  spines 
  on 
  its 
  anterior 
  margin, 
  ar- 
  

   ranged 
  nearly 
  in 
  a 
  semicircle, 
  and 
  are 
  equidistant, 
  and 
  behind 
  this 
  

   the 
  lateral 
  margins 
  are 
  denticulated. 
  The 
  carapace 
  is 
  densely 
  

   pubescent 
  above 
  in 
  front, 
  and 
  its 
  dorsal 
  surface 
  is 
  bordered 
  anteriorly 
  

   by 
  a 
  suture, 
  which 
  is 
  continued 
  backward 
  nearly 
  as 
  far 
  as 
  the 
  cer- 
  

   vical 
  suture, 
  which 
  is 
  deep 
  and 
  well 
  defiued. 
  The 
  segments 
  of 
  tbe 
  

   postabdomen 
  are 
  nearly 
  smooth, 
  but 
  clothed 
  with 
  a 
  few 
  hairs 
  ; 
  the 
  

   terminal 
  segment 
  slightly 
  transverse, 
  with 
  the 
  posterior 
  margin 
  

   straight 
  and 
  unarmed. 
  The 
  eyes, 
  which 
  have 
  very 
  short 
  and 
  thick 
  

   peduncles, 
  are 
  well 
  nigh 
  concealed 
  beneath 
  the 
  front 
  in 
  a 
  dorsal 
  view. 
  

   The 
  antennules 
  are 
  short, 
  the 
  peduncles 
  scarcely 
  reaching 
  beyond 
  

   the 
  front, 
  and 
  each 
  bearing 
  two 
  subequalflagella. 
  The 
  antennae 
  are 
  

   little 
  longer 
  than 
  the 
  carapace 
  ; 
  the 
  slender 
  peduncles 
  reach 
  some- 
  

   what 
  beyond 
  the 
  front 
  ; 
  the 
  peniiltimate 
  and 
  terminal 
  joints 
  are 
  

   short, 
  and 
  clothed 
  above 
  with 
  long 
  hairs 
  ; 
  the 
  llagella 
  of 
  the 
  an- 
  

   tennae 
  terminate 
  in 
  a 
  pencil 
  of 
  hairs, 
  and 
  the 
  several 
  joints 
  also 
  bear 
  

   a 
  few 
  seta*. 
  The 
  chelipedes 
  are 
  subequal 
  and 
  moderately 
  robust 
  ; 
  

   the 
  merus-joints 
  unarmed 
  and 
  somewhat 
  hairy 
  ; 
  the 
  hairs 
  longest 
  

   and 
  most 
  abundant 
  along 
  the 
  inferior 
  margins 
  ; 
  the 
  wrists 
  are 
  short, 
  

   thinly 
  clothed 
  with 
  hair, 
  and 
  having 
  a 
  few 
  minute 
  spinules 
  along 
  

   their 
  upper 
  margins, 
  of 
  which 
  the 
  anterior 
  one 
  is 
  the 
  most 
  promi- 
  

   nent 
  ; 
  the 
  palms 
  longer 
  than 
  broad, 
  somewhat 
  turgid, 
  rovmded 
  above 
  

   and 
  below, 
  and 
  thinly 
  clothed 
  with 
  hair, 
  which 
  is 
  arranged 
  iu 
  dis- 
  

   tant 
  longitudinal 
  lines 
  ; 
  the 
  fingers 
  are 
  hairy, 
  much 
  shorter 
  than 
  the 
  

   palms, 
  thickened 
  at 
  base, 
  dentated 
  on 
  their 
  inner 
  margins, 
  with 
  their 
  

   apices 
  slightly 
  crossed 
  when 
  closed, 
  the 
  upper 
  much 
  curved. 
  The 
  

   second 
  legs 
  have 
  the 
  under 
  margins 
  of 
  the 
  merus-joints 
  densely 
  

   fringed 
  with 
  hair, 
  and 
  the 
  last 
  three 
  joints 
  are 
  also 
  hairy 
  ; 
  the 
  

   penultimate 
  joint 
  longer 
  than 
  tho 
  preceding, 
  moderately 
  dilated 
  and 
  

   compressed 
  ; 
  dactyli 
  shorter 
  than 
  the 
  preceding 
  joint 
  ; 
  the 
  third 
  legs 
  

   are 
  similar 
  to 
  the 
  second, 
  but 
  the 
  merus 
  is 
  less 
  hairy 
  below, 
  and 
  the 
  

   propus 
  is 
  shorter 
  ; 
  the 
  fourth 
  and 
  fifth 
  legs 
  are 
  much 
  shorter 
  and 
  

   slenderer 
  than 
  the 
  foregoing, 
  and 
  tho 
  last 
  three 
  joints 
  are 
  more 
  or 
  

   less 
  hairy, 
  the 
  hairs 
  thickest 
  along 
  the 
  inferior 
  margins 
  of 
  the 
  pro- 
  

   pus. 
  The 
  rami 
  of 
  the 
  uropoda 
  are 
  broad, 
  with 
  the 
  distal 
  margins 
  

   straight 
  : 
  they 
  about 
  reach 
  to 
  the 
  distal 
  end 
  of 
  the 
  terminal 
  seg- 
  

   ment 
  of 
  the 
  postabdomen. 
  Colour 
  (in 
  spirit) 
  yellowish 
  white. 
  The 
  

   length 
  of 
  the 
  largest 
  specimen 
  does 
  not 
  exceed 
  9 
  lines 
  (19 
  raillim.). 
  

  

  