﻿352 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  Where 
  the 
  pores 
  are 
  fewer 
  the 
  two 
  Hnes 
  first 
  mentioned 
  can 
  usually 
  be 
  

   distinguished, 
  but 
  are 
  less 
  crowded 
  than 
  in 
  the 
  extreme 
  form, 
  while 
  the 
  

   third 
  row 
  is 
  represented 
  by 
  two 
  or 
  three 
  scattering 
  pores 
  or 
  not 
  at 
  all, 
  

   and 
  the 
  pores 
  at 
  the 
  first 
  incision 
  are 
  two 
  or 
  three 
  in 
  a 
  group 
  close 
  to 
  the 
  

   ends 
  of 
  the 
  chitinous 
  processes. 
  

  

  The 
  second 
  stage 
  of 
  A. 
  a 
  n 
  c 
  y 
  1 
  u 
  s 
  seems 
  not 
  always 
  definitively 
  differ- 
  

   ent 
  from 
  the 
  same 
  stage 
  ofA. 
  ostreaeformis, 
  I 
  have 
  seen 
  in 
  mounts 
  

   from 
  undoubted 
  A. 
  a 
  n 
  c 
  y 
  1 
  u 
  s 
  material 
  one 
  or 
  two 
  second 
  stage 
  speci- 
  

   mens, 
  which 
  had 
  the 
  small, 
  narrow 
  yet 
  distinct 
  second 
  lobes 
  together 
  

   with 
  absence 
  of 
  the 
  plates 
  that 
  characterize 
  A. 
  ostreaeformis. 
  

   Similarly, 
  I 
  have 
  seen 
  in 
  A. 
  ostreaeformis 
  mounts 
  second 
  stage 
  

   specimens 
  that 
  suggest 
  A. 
  ancylus. 
  Of 
  course, 
  it 
  is 
  always 
  possible 
  

   that 
  the 
  two 
  species 
  are 
  breeding 
  side 
  by 
  side 
  and 
  may 
  be 
  taken 
  at 
  the 
  

   same 
  time 
  in 
  the 
  younger 
  forms, 
  even 
  if 
  they 
  have 
  not 
  been 
  so 
  taken 
  in 
  

   the 
  adult 
  stage. 
  It 
  seems 
  to 
  me 
  that, 
  in 
  distinction 
  between 
  the 
  two 
  

   species, 
  if 
  fringing 
  plates 
  are 
  present, 
  whether 
  or 
  not 
  rudimentary 
  lobes 
  

   appear, 
  it 
  is 
  pretty 
  surely 
  not 
  A. 
  ostreaeformis 
  but 
  is 
  presumably 
  

   A. 
  ancylus. 
  If 
  plates 
  are 
  not 
  discernible, 
  and 
  a 
  second 
  pair 
  of 
  lobes 
  

   appears, 
  it 
  is 
  pretty 
  safely 
  the 
  former 
  species. 
  But, 
  where 
  there 
  are 
  

   neither 
  plates 
  nor 
  second 
  lobes 
  to 
  be 
  discovered, 
  additional 
  evidence 
  

   should 
  be 
  sought 
  In 
  any 
  case 
  an 
  identification 
  from 
  second 
  stage 
  

   materia] 
  may 
  safely 
  be 
  modified 
  with 
  '' 
  probably." 
  

  

  Aspidiotus 
  ostreaeformis 
  Curtis 
  

  

  PLATE 
  14 
  AND 
  PLATE 
  1 
  5, 
  FIGURE 
  2 
  

  

  A. 
  ostreaeformis 
  is 
  one 
  of 
  the 
  large 
  species, 
  the 
  adult 
  female 
  

   often 
  attaining 
  a 
  diameter 
  of 
  \\ 
  mm 
  according 
  to 
  Dr 
  Marlatt. 
  He 
  

   gives 
  an 
  extended 
  description 
  and 
  a 
  beautiful 
  figure 
  on 
  page 
  8 
  1 
  of 
  the 
  

   Proceedings 
  of 
  the 
  ilth 
  annual 
  ?neeting 
  of 
  the 
  association 
  of 
  economic 
  entor 
  

   mologists 
  (U. 
  S. 
  dep't 
  agric. 
  div. 
  ent. 
  Bui. 
  20, 
  n. 
  s.). 
  

  

  The 
  median 
  lobes 
  of 
  this 
  species 
  vary 
  somewhat 
  in 
  shape, 
  but 
  are 
  in 
  gen- 
  

   eral 
  broad 
  with 
  a 
  distinct 
  though 
  shallow 
  notch 
  on 
  the 
  outer 
  margin. 
  The 
  

   second 
  pair 
  are 
  much 
  smaller 
  but 
  usually 
  easy 
  to 
  distinguish 
  and 
  quite 
  

   characteristic 
  in 
  shape. 
  They 
  are 
  at 
  least 
  often 
  considerably 
  narrower 
  in 
  

   proportion 
  than 
  in 
  the 
  specimen 
  represented 
  in 
  my 
  figure. 
  Both 
  pairs 
  are 
  

   usually 
  heavily 
  chitinized, 
  and 
  sometimes 
  a 
  rudimentary 
  third 
  pair 
  seems 
  

   to 
  be 
  indicated 
  by 
  the 
  arrangement 
  of 
  chitin 
  beyond 
  the 
  second 
  incision. 
  

  

  The 
  spines 
  are 
  as 
  in 
  alHed 
  species; 
  the 
  plates 
  are 
  inconspicuous, 
  but 
  

   two 
  short 
  stout 
  ones 
  are 
  usually 
  to 
  be 
  discerned 
  at 
  each 
  incision. 
  

  

  