﻿264 
  Transactions. 
  — 
  Zoolor/y. 
  

  

  It 
  scarcely 
  needs 
  more 
  than 
  a 
  glance, 
  however, 
  at 
  the 
  lip 
  ancl 
  maxillse 
  to 
  

   decide 
  that 
  this 
  interesting 
  spider 
  does 
  not 
  helong 
  to 
  Argyroveta, 
  but, 
  

   indeed, 
  that 
  in 
  the 
  form 
  of 
  these 
  appendages 
  it 
  differs 
  very 
  strikingly 
  from 
  

   that 
  genus. 
  Dr. 
  L. 
  Koch 
  describes 
  two 
  closely 
  allied 
  species 
  (Arachniden 
  

   Australiens, 
  p. 
  345-351, 
  plate 
  xsix., 
  figs. 
  1 
  and 
  2) 
  referring 
  them 
  to 
  the 
  

   genus 
  Desis, 
  founded 
  by 
  AValckenaer 
  on 
  a 
  single 
  species, 
  Desis 
  dysderoides 
  

   from 
  New 
  Guinea. 
  

  

  The 
  following 
  are 
  the 
  characters 
  of 
  the 
  genus 
  Desis, 
  as 
  given 
  by 
  

   Walckenaer.='= 
  

  

  "Eyes 
  eight, 
  in 
  two 
  lines, 
  the 
  anterior 
  very 
  close 
  to 
  the 
  anterior 
  margin 
  

   of 
  the 
  cephalo 
  thorax, 
  curved 
  backwards, 
  and 
  forming 
  an 
  open 
  crescent 
  ; 
  the 
  

   eyes 
  forming 
  the 
  intermediate 
  square, 
  larger 
  than 
  the 
  lateral 
  eyes, 
  which 
  

   are 
  situated 
  on 
  a 
  slightly 
  raised 
  tubercle. 
  

  

  " 
  Lip 
  elongated, 
  with 
  parallel 
  sides, 
  deeply 
  notched 
  at 
  its 
  extremity. 
  

  

  "Maxillse 
  straight, 
  diverging, 
  dilated 
  at 
  their 
  base, 
  pointed 
  at 
  their 
  

   extremity. 
  

  

  " 
  Legs 
  strong, 
  suited 
  for 
  running; 
  the 
  anterior 
  longer 
  than 
  the 
  posterior 
  ; 
  

   the 
  first 
  pair 
  the 
  longest, 
  the 
  second 
  next, 
  the 
  third 
  pair 
  the 
  shortest." 
  

  

  The 
  above 
  characters 
  are 
  supplemented 
  in 
  the 
  description 
  of 
  the 
  species 
  

   Desis 
  dysderoides, 
  which 
  I 
  subjoin. 
  

  

  "Abdomen 
  oval, 
  convex 
  above 
  and 
  below, 
  of 
  a 
  uniform 
  pale 
  grey. 
  Cepha- 
  

   lothorax, 
  mandibles, 
  sternum, 
  legs 
  and 
  palpi 
  coral 
  red. 
  Mandibles 
  long 
  

   and 
  strong, 
  directed 
  forwards. 
  

  

  " 
  New 
  Guinea. 
  Quoy 
  and 
  Gaimard. 
  

  

  "Aspect 
  of 
  Dysdera 
  erythrina. 
  Cephalothorax 
  as 
  long 
  and 
  as 
  large 
  as 
  the 
  

   abdomen, 
  sides 
  almost 
  parallel, 
  scarcely 
  at 
  all 
  narrowed 
  anteriorly, 
  flattened. 
  

   Sternum 
  without 
  spots, 
  without 
  eminences, 
  and 
  clothed 
  at 
  the 
  insertion 
  of 
  

   the 
  legs 
  with 
  yellow 
  hair. 
  The 
  mandibles 
  are 
  very 
  strong, 
  directed 
  forwards 
  

   as 
  in 
  Dysdera, 
  as 
  long 
  as 
  the 
  cepthalothorax, 
  cylindroid, 
  with 
  the 
  claws 
  of 
  

   a 
  red 
  brown, 
  elongated, 
  half 
  opened 
  and 
  not 
  completely 
  folded 
  back 
  in 
  the 
  

   groove, 
  which 
  last 
  is 
  toothed. 
  The 
  teeth 
  are 
  prominent 
  and 
  number 
  eight 
  

   or 
  nine 
  as 
  in 
  Dysdera 
  erythrina. 
  The 
  legs 
  have 
  the 
  tarsus 
  provided 
  with 
  

   three 
  claws, 
  of 
  which 
  one 
  is 
  very 
  short 
  and 
  almost 
  hidden 
  in 
  the 
  hairs." 
  f 
  

  

  The 
  agreement 
  of 
  our 
  spider 
  with 
  the 
  above 
  characters 
  is 
  so 
  close 
  that 
  

   there 
  can 
  be 
  no 
  doubt 
  as 
  to 
  the 
  propriety 
  of 
  placing 
  it 
  in 
  this 
  genus. 
  

  

  Desis 
  rohsoni, 
  nov. 
  s^. 
  

  

  Male. 
  — 
  Cephalothorax 
  moderately 
  dark 
  mahogany 
  brown, 
  darkening 
  

   towards 
  the 
  facial 
  border, 
  paling 
  towards 
  the 
  sides 
  and 
  posterior 
  border 
  of 
  

   the 
  thorax, 
  sparingly 
  clothed 
  with 
  short 
  hairs. 
  Angles 
  of 
  the 
  caput 
  bor- 
  

   dered 
  with 
  black. 
  

  

  * 
  Histoire 
  des 
  Apteres, 
  Vol. 
  I, 
  p. 
  610, 
  plate 
  it., 
  figs. 
  15 
  a 
  and 
  &. 
  

   I 
  Histoire 
  des 
  Apteres, 
  Vol, 
  I., 
  p. 
  611. 
  

  

  