﻿Maskkll. 
  — 
  On 
  some 
  Coccidae 
  in 
  New 
  Zealand. 
  191 
  

  

  the 
  focus 
  of 
  tlae 
  curve 
  (this 
  does 
  not 
  hold 
  good 
  for 
  all 
  genera), 
  and 
  it 
  is 
  

   surrounded 
  by 
  groups 
  of 
  minute 
  circular 
  marks, 
  arranged 
  like 
  bunches 
  of 
  

   grapes, 
  whilst 
  other 
  marks 
  are 
  scattered 
  singly 
  over 
  the 
  abdominal 
  region. 
  

   These 
  marks, 
  which 
  are 
  in 
  reality 
  the 
  open 
  ends 
  of 
  tubes, 
  are 
  supposed 
  to 
  

   be 
  a 
  kind 
  of 
  spinnerets 
  from 
  which 
  the 
  insect 
  builds 
  round 
  itself 
  the 
  shield 
  

   of 
  which 
  I 
  spoke 
  just 
  now. 
  Some 
  of 
  the 
  chief 
  characters 
  upon 
  which 
  the 
  

   specific 
  differences 
  of 
  Diaspidse 
  are 
  founded, 
  are 
  the 
  presence 
  or 
  absence 
  of 
  

   these 
  spinnerets, 
  the 
  number 
  of 
  the 
  groups, 
  their 
  continuity 
  or 
  separation, 
  

   and 
  the 
  number 
  of 
  openings 
  in 
  each 
  group. 
  There 
  are 
  other 
  features, 
  such 
  

   as 
  difference 
  of 
  outline 
  in 
  the 
  body, 
  difference 
  of 
  shape 
  of 
  shield, 
  difference 
  

   of 
  form 
  of 
  the 
  male, 
  difference 
  of 
  length 
  in 
  the 
  thoracic 
  band 
  of 
  the 
  male. 
  

   But 
  these 
  are 
  often 
  more 
  properly 
  generic 
  than 
  specific 
  differences; 
  more- 
  

   over, 
  the 
  excessive 
  rarity 
  of 
  the 
  male 
  insects 
  renders 
  it 
  very 
  difficult 
  to 
  

   arrive 
  at 
  certainty 
  from 
  them 
  ; 
  whereas 
  the 
  abdominal 
  markings 
  of 
  the 
  

   females 
  are 
  in 
  general 
  so 
  distinctly 
  clear 
  that 
  they 
  offer 
  an 
  excellent 
  means 
  

   of 
  distinguishing 
  between 
  individuals. 
  

  

  The 
  mouth 
  is, 
  as 
  I 
  said 
  above, 
  absent 
  entirely 
  in 
  the 
  male 
  insect 
  in 
  its 
  

   perfect 
  state. 
  The 
  mouth 
  of 
  the 
  female 
  consists 
  of 
  a 
  rostrum, 
  or 
  beak, 
  on 
  

   the 
  underside 
  of 
  the 
  head, 
  some 
  little 
  way 
  from 
  its 
  anterior 
  edge. 
  It 
  appears 
  

   in 
  the 
  DiaspidaB 
  to 
  have 
  no 
  joints, 
  and 
  from 
  its 
  interior 
  start 
  three 
  (or 
  in 
  

   some 
  cases 
  four) 
  very 
  long, 
  thin 
  tubular 
  bristles, 
  which, 
  I 
  suppose, 
  the 
  insect 
  

   inserts 
  into 
  the 
  stomata 
  or 
  minute 
  orifices 
  of 
  the 
  plant 
  on 
  which 
  it 
  lives, 
  for 
  

   the 
  purpose 
  of 
  withdrawing 
  thence 
  its 
  food. 
  My 
  plate 
  V., 
  figs, 
  le 
  and 
  /, 
  

   show 
  this 
  rostrum 
  (which 
  is, 
  with 
  modifications, 
  common 
  to 
  all 
  Coccidas), 
  as 
  

   it 
  appears 
  on 
  the 
  insect, 
  and 
  as 
  it 
  shows 
  after 
  mounting 
  for 
  the 
  microscope. 
  

  

  So 
  much 
  for 
  the 
  general 
  features 
  of 
  the 
  female. 
  The 
  male 
  differs 
  a 
  

   good 
  deal 
  in 
  shape 
  in 
  various 
  species, 
  but, 
  as 
  far 
  as 
  it 
  is 
  known, 
  has 
  always 
  

   two 
  wings, 
  six 
  legs 
  terminated 
  by 
  a 
  single 
  claw, 
  antennae 
  usually 
  of 
  ten 
  

   joints, 
  and, 
  at 
  the 
  posterior 
  end 
  of 
  the 
  abdomen 
  a 
  long 
  double 
  spike, 
  

   Bometimes 
  nearly 
  equal 
  in 
  length 
  to 
  the 
  whole 
  body. 
  The 
  insect 
  undergoes 
  

   three 
  transformations. 
  From 
  the 
  Qgg 
  it 
  emerges 
  as 
  an 
  oval 
  insect 
  similar 
  

   in 
  all 
  respects 
  to 
  the 
  female 
  ; 
  in 
  some 
  species 
  it 
  surrounds 
  itself 
  with 
  a 
  

   shield 
  like 
  that 
  of 
  the 
  female, 
  in 
  others 
  the 
  shield 
  is 
  much 
  longer 
  and 
  

   narrower. 
  After 
  a 
  time 
  it 
  discards 
  its 
  first 
  pellicle 
  and 
  remains 
  in 
  the 
  

   shield, 
  gradually 
  changing 
  into 
  the 
  pupa 
  stage. 
  During 
  this 
  process, 
  

   according 
  to 
  M. 
  Signoret, 
  the 
  successive 
  formation 
  of 
  the 
  eyes, 
  wings, 
  

   antennae, 
  and 
  abdominal 
  sj)ike 
  may 
  be 
  observed. 
  I 
  have 
  s^jecimens 
  of 
  

   J)up8e 
  of 
  Aspicliotus 
  epidenclri, 
  in 
  which 
  this 
  formation 
  is 
  apparent* 
  The 
  

   first 
  pellicle 
  is 
  the 
  only 
  one 
  which 
  remains 
  attached 
  to 
  the 
  shield, 
  as 
  the 
  

   insect 
  emerges 
  from 
  the 
  pupa 
  stage, 
  winged 
  and 
  perfect 
  ; 
  consequently, 
  in 
  

   some 
  species 
  it 
  is 
  possible 
  to 
  distinguish 
  between 
  the 
  shields 
  of 
  the 
  two 
  

   sexes 
  simply 
  from 
  the 
  presence 
  in 
  one 
  of 
  two 
  pellicles, 
  in 
  the 
  other 
  of 
  only 
  

   pne. 
  

  

  