﻿CRUSTACEA. 
  539 
  

  

  4G. 
  Goniosoma 
  natator 
  (Herbst). 
  

  

  A 
  female 
  was 
  collected 
  at 
  Poivro 
  Island, 
  or 
  lie 
  dcs 
  rtoches, 
  13- 
  

   20 
  fms. 
  (No. 
  183). 
  

  

  Specimens 
  arc 
  in 
  the 
  Britisli-llnseum 
  collection 
  from 
  the 
  folloAving 
  

   localities: 
  — 
  Port 
  Natal; 
  Indian 
  Ocean 
  {Gen. 
  Hardwklce) 
  ; 
  Penang 
  

   {Dr. 
  Cantor); 
  Philippines 
  (C't<»u'rt^); 
  and 
  Shanghai. 
  

  

  47. 
  Thalamita 
  sima, 
  M.-Edw. 
  

  

  Several 
  young 
  specimens 
  were 
  collected 
  at 
  the 
  Seychelles, 
  4-12 
  

   fms. 
  (No. 
  194) 
  ; 
  a 
  series 
  of 
  specimens 
  of 
  both 
  sexes 
  and 
  varying 
  

   sizes 
  at 
  Poivre 
  Island 
  and 
  He 
  des 
  Roches, 
  13-20 
  fms. 
  (No. 
  183); 
  

   a 
  young 
  male 
  at 
  the 
  Glorioso 
  Islands, 
  7-10 
  fms. 
  (No. 
  219); 
  and 
  a 
  

   female 
  on 
  the 
  beach 
  at 
  Mozambique 
  (No. 
  224). 
  

  

  I 
  have 
  remarked 
  upon 
  the 
  distribution 
  of 
  this 
  common 
  species 
  on 
  

   p. 
  231. 
  

  

  48. 
  Thalamita 
  quadrilobata. 
  (Plate 
  XLVIII. 
  fig. 
  B.) 
  

  

  The 
  carapace 
  is 
  markedly 
  transverse, 
  of 
  the 
  form 
  usual 
  in 
  this 
  

   genus, 
  depressed, 
  with 
  the 
  lateral 
  margins 
  forming 
  nearly 
  a 
  right 
  

   angle 
  with 
  the 
  front 
  ; 
  the 
  carapace 
  marked 
  with 
  transverse 
  lines, 
  

   one 
  of 
  which 
  passes 
  across 
  it 
  at 
  its 
  greatest 
  width 
  from 
  the 
  bases 
  of 
  

   the 
  fifth 
  lateral 
  marginal 
  teeth, 
  being 
  interrupted 
  only 
  on 
  the 
  sides 
  

   of 
  the 
  gastric 
  region 
  by 
  the 
  shallow 
  depression 
  indicative 
  of 
  the 
  

   cervical 
  suture. 
  The 
  frontal 
  margin 
  is 
  divided 
  into 
  four 
  squarely- 
  

   truncated 
  lobes 
  of 
  nearly 
  equal 
  width 
  ; 
  the 
  median 
  lobes 
  are 
  more 
  

   prominent 
  than 
  the 
  lateral, 
  with 
  their 
  anterior 
  margins 
  very 
  shallow, 
  

   concave, 
  or 
  excavate, 
  and 
  are 
  separated 
  by 
  a 
  narrow 
  median 
  in- 
  

   cision 
  ; 
  the 
  lateral 
  lobes 
  have 
  a 
  straight 
  margin. 
  On 
  the 
  post- 
  

   frontal 
  part 
  of 
  the 
  carapace, 
  on 
  either 
  side 
  of 
  the 
  middle 
  line, 
  are 
  

   two 
  slight 
  prominences. 
  The 
  upper 
  margin 
  of 
  the 
  orbit 
  has 
  two 
  

   distinct 
  fissures, 
  the 
  lower 
  margin 
  is 
  also 
  marked 
  by 
  a 
  deep 
  fissure 
  ; 
  

   and 
  the 
  inner 
  suborbital 
  lobe 
  is 
  very 
  prominent 
  and 
  squarely 
  

   truncated. 
  There 
  are 
  five 
  very 
  strong, 
  acute, 
  subequal, 
  lateral 
  

   marginal 
  spines 
  ; 
  the 
  postero-lateral 
  margins 
  are 
  deeply 
  concave 
  ; 
  

   the 
  posterior 
  margin 
  bounded 
  by 
  a 
  raised 
  line. 
  The 
  postabdomen 
  of 
  

   the 
  male 
  is 
  five-jointed; 
  the 
  third 
  to 
  fifth 
  joints 
  coulesccnt 
  ; 
  the 
  

   basal 
  autennal 
  joint 
  is 
  armed 
  with 
  three 
  strong 
  spines. 
  The 
  cheli- 
  

   pedes 
  are 
  massive 
  and 
  of 
  equal 
  size 
  ; 
  the 
  merus 
  or 
  arm 
  has 
  its 
  

   posterior 
  margin 
  obtusely 
  angulated, 
  and 
  its 
  anterior 
  margin 
  armed 
  

   with 
  three 
  principal 
  spines 
  and 
  one 
  or 
  two 
  very 
  small 
  intervening 
  

   ones 
  ; 
  the 
  wrist 
  granulated 
  externally, 
  with 
  two 
  small 
  spines 
  on 
  its 
  

   outer 
  surface 
  and 
  a 
  very 
  strong 
  spine 
  on 
  its 
  inner 
  margin 
  ; 
  the 
  palm 
  

   granulated 
  above 
  and 
  armed 
  with 
  five 
  or 
  six 
  spines, 
  externally 
  

   traversed 
  by 
  three 
  granulated 
  lines, 
  of 
  which 
  the 
  lowermost 
  is 
  pro- 
  

   longed 
  along 
  the 
  outer 
  margin 
  of 
  the 
  immobile 
  finger 
  ; 
  the 
  fingers 
  arc 
  

   very 
  distinctly 
  denticulated, 
  those 
  of 
  the 
  right 
  side 
  having 
  each 
  a 
  

   larger 
  subbasal 
  tooth. 
  The 
  three 
  following 
  legs 
  arc 
  slender 
  ; 
  the 
  

  

  