﻿Powell. 
  — 
  On 
  Desis 
  robsoui, 
  263 
  

  

  Fig. 
  B. 
  i. 
  Cypris 
  Uttora.lis 
  : 
  [a) 
  superior 
  antennas 
  ; 
  (&) 
  inferior 
  antennse 
  ; 
  (c 
  and 
  cl) 
  first 
  

   and 
  second 
  pair 
  of 
  legs. 
  

  

  2. 
  Cythere 
  atra 
  : 
  [a) 
  portion 
  of 
  valve.; 
  {b 
  and 
  c) 
  legs 
  of 
  first 
  and 
  second 
  pairs. 
  

  

  3. 
  Loxoconcha 
  punctata 
  : 
  {a) 
  superior 
  antennte 
  ; 
  (5) 
  inferior 
  antennte 
  ; 
  (c) 
  man- 
  

  

  dible 
  ; 
  (cl) 
  maxillas 
  ; 
  {e) 
  third 
  pair 
  of 
  legs 
  ; 
  (/) 
  outer 
  margin 
  of 
  valve 
  ; 
  (g) 
  

   hinge-line; 
  (7i) 
  abdominal 
  lobe 
  ; 
  (it) 
  post-abdominal 
  ramus. 
  

  

  Fig. 
  0. 
  1. 
  Cypiere 
  atra 
  : 
  (a) 
  superior 
  antenna3 
  ; 
  {&) 
  inferior 
  antennae. 
  

  

  2. 
  Cythere 
  truncata 
  : 
  (a) 
  sf.perior 
  antenna 
  ; 
  (6) 
  inferior 
  antennas 
  ; 
  (c) 
  mandible. 
  

   3. 
  Philomedes 
  agilis 
  : 
  (a) 
  central 
  portion 
  of 
  valves 
  showing 
  lucid 
  spots 
  ; 
  (&) 
  por- 
  

   tion 
  of 
  seta 
  on 
  natatory 
  branch 
  of 
  lower 
  antennae 
  , 
  female 
  ; 
  (c) 
  secondary 
  

   joint 
  of 
  lower 
  antennas, 
  male 
  ; 
  [d) 
  same, 
  female 
  ; 
  [e) 
  extremity 
  of 
  oviferous 
  

   foot. 
  

  

  Fig. 
  D. 
  1. 
  Philomedes 
  agilia 
  : 
  {a) 
  superior 
  antennte, 
  male; 
  (&) 
  same, 
  female 
  ; 
  (c) 
  natatory 
  

   branch 
  of 
  inferior 
  antenna, 
  male 
  ; 
  [d) 
  same, 
  female 
  ; 
  (e) 
  mandibular 
  foot 
  ; 
  

   (/) 
  p-ost-abdominal 
  laminae 
  ; 
  (g) 
  second 
  maxilla. 
  

  

  2. 
  Cyclo2)snovce-zealandias, 
  female: 
  (a, 
  &) 
  superior 
  and 
  inferior 
  antenna 
  ; 
  (r?) 
  second 
  

  

  foot-jaws, 
  outer 
  branch 
  ; 
  (e) 
  inner 
  branch 
  ; 
  (/) 
  leg 
  of 
  third 
  pair 
  ; 
  [g) 
  leg 
  of 
  

   fifth 
  pair 
  ; 
  [h) 
  caudal 
  lamella 
  and 
  seta 
  ; 
  {k) 
  second 
  segment 
  of 
  abdomen 
  

   with 
  triple 
  spines 
  ; 
  (Z) 
  superior 
  antenna 
  of 
  male. 
  

  

  3. 
  Arpacticus 
  bairdii, 
  female 
  : 
  (a) 
  foot-jaws 
  ; 
  (6) 
  first 
  pair 
  of 
  legs. 
  

  

  Fig. 
  E. 
  1. 
  Arpacticus 
  bairdii, 
  female 
  : 
  (a) 
  inferior 
  antenna 
  ; 
  (5) 
  superior 
  antenna 
  ; 
  (c) 
  

  

  cephalothorax 
  from 
  above 
  ; 
  (d) 
  third 
  pair 
  of 
  legs 
  ; 
  (e) 
  fifth 
  isaix 
  of 
  legs 
  ; 
  (/) 
  

   abdominal 
  segments 
  and 
  caudal 
  seta. 
  

  

  2. 
  Daphnia 
  obtusata 
  : 
  {a) 
  head, 
  seen 
  from 
  above 
  ; 
  (6) 
  superior 
  antenna 
  ; 
  (c) 
  

  

  mandibles 
  ; 
  [d) 
  extremity 
  of 
  abdomen 
  ; 
  (e) 
  young, 
  taken 
  from 
  carapace 
  of 
  

   parent. 
  

  

  3. 
  Chydorus 
  minutus 
  : 
  (a) 
  inferior 
  antenna 
  ; 
  (6) 
  superior 
  antenna 
  ; 
  (c) 
  extremity 
  

  

  of 
  abdomen. 
  

  

  4. 
  Lepidurus 
  Mrkii 
  : 
  (a) 
  foot 
  of 
  the 
  first 
  23air. 
  

  

  5. 
  Lepidurus 
  compressus 
  : 
  (a) 
  foot 
  of 
  the 
  first 
  pair. 
  

  

  Art. 
  XXII. 
  — 
  On 
  Desis 
  robsoiii, 
  a 
  Marine 
  Sincler, 
  from 
  Cape 
  Campbell. 
  

  

  By 
  Llewellyn 
  Powell, 
  M.D. 
  

  

  [Read 
  before 
  the 
  Philosophical 
  Institute 
  of 
  Canterbury, 
  1th 
  November, 
  1878.] 
  

  

  Plate 
  XII. 
  

  

  In 
  tlie 
  tenth 
  volume 
  of 
  the 
  Transactions, 
  p. 
  299, 
  is 
  a 
  short 
  description 
  of 
  

   a 
  spider, 
  discovered 
  inhabiting 
  old 
  Lithodomus 
  holes, 
  beneath 
  the 
  surface 
  

   of 
  tidal 
  pools, 
  by 
  Mr. 
  C. 
  H. 
  Eobson, 
  at 
  Cape 
  Campbell. 
  Dr. 
  Hector 
  in 
  a 
  note 
  

   states 
  that 
  this 
  spider 
  is 
  allied 
  to 
  the 
  genus 
  Argyroneta, 
  and 
  pro^DOses 
  for 
  it 
  

   the 
  name 
  Argyroneta 
  marina. 
  

  

  