﻿SCALE 
  INSECTS 
  OF 
  IMPORTANCE 
  353 
  

  

  The 
  chitinous 
  processes 
  are 
  subequal 
  on 
  the 
  two 
  sides 
  of 
  each 
  incision. 
  

   They 
  are 
  quite 
  large 
  beside 
  the 
  first 
  incision 
  but 
  are 
  somewhat 
  irregular 
  

   in 
  shape 
  and 
  usually 
  not 
  so 
  strongly 
  curved 
  on 
  the 
  inner 
  side 
  as 
  is 
  the 
  

   case 
  in 
  A. 
  p 
  e 
  r 
  n 
  i 
  c 
  i 
  o 
  s 
  u 
  s, 
  and 
  those 
  on 
  the 
  inner 
  edges 
  of 
  the 
  median 
  

   lobes 
  are 
  variable, 
  sometimes 
  easily 
  detected 
  and 
  in 
  other 
  cases 
  vague. 
  

   and 
  indefinite. 
  

  

  The 
  ventral 
  glands 
  in 
  the 
  adult 
  female 
  are 
  quite 
  numerous 
  and 
  are 
  

   usually 
  in 
  compact, 
  nearly 
  circular 
  groups, 
  while 
  those 
  of 
  A. 
  an 
  c 
  y 
  1 
  u 
  s 
  

   are 
  more 
  likely 
  to 
  be 
  linearly 
  arranged. 
  Dr 
  Marlatt 
  gives 
  the 
  numbers 
  

   as 
  averaging 
  six 
  for 
  the 
  anterior 
  group, 
  which 
  is 
  usually 
  much 
  the 
  smaller, 
  

   and 
  lo 
  or 
  12 
  for 
  each 
  of 
  the 
  lateral 
  groups, 
  but 
  the 
  numbers 
  vary 
  

   quite 
  considerably. 
  

  

  The 
  thickenings 
  in 
  the 
  region 
  of 
  the 
  ventral 
  glands 
  are 
  indefinite 
  and 
  

   look 
  somewhat 
  like 
  crumplings 
  or 
  foldings 
  of 
  the 
  body 
  wall. 
  

  

  The 
  anus 
  is 
  small 
  and 
  quite 
  distant 
  from 
  the 
  median 
  lobes. 
  The 
  

   margins, 
  however, 
  run 
  up 
  to 
  embrace 
  it. 
  

  

  Dr 
  Marlatt 
  says 
  : 
  

  

  The 
  dorsal 
  pores 
  are 
  quite 
  characteristic. 
  There 
  are 
  usually 
  two 
  

   between 
  the 
  first 
  pair 
  of 
  processes 
  and 
  a 
  row 
  of 
  five 
  or 
  six 
  extending 
  

   from 
  the 
  second 
  pair 
  of 
  processes 
  and 
  after 
  a 
  considerable 
  interval, 
  con- 
  

   tinued 
  near 
  the 
  lower 
  group 
  of 
  paragenital 
  glands 
  in 
  one 
  or 
  two 
  addi- 
  

   tional 
  pores. 
  A 
  lateral 
  row 
  of 
  about 
  10 
  or 
  11 
  pores 
  extends 
  from 
  near 
  

   the 
  base 
  of 
  the 
  first 
  pair 
  of 
  spines 
  to 
  the 
  lateral 
  chitinous 
  thickenings. 
  

   Differing 
  from 
  most 
  of 
  its 
  near 
  allies, 
  it 
  has 
  a 
  group 
  of 
  six 
  or 
  seven 
  pores 
  

   near 
  the 
  basal 
  angles 
  of 
  this 
  segment. 
  

  

  In 
  the 
  next 
  to 
  the 
  last 
  sentence 
  "first 
  pair 
  of 
  spines" 
  means 
  the 
  first 
  

   spines 
  beyond 
  those 
  associated 
  with 
  lobes, 
  as 
  I 
  think 
  will 
  be 
  seen 
  on 
  

   study 
  of 
  this 
  figure. 
  The 
  number 
  of 
  these 
  pores 
  varies 
  somewhat, 
  yet 
  

   there 
  is 
  a 
  certain 
  characteristic 
  general 
  appearance 
  in 
  this 
  arrangement 
  

   that 
  becomes 
  familiar 
  and 
  at 
  sight 
  suggests 
  A. 
  ostreaeformis 
  to 
  a 
  

   student 
  of 
  these 
  forms. 
  I 
  have 
  often 
  found 
  three 
  pores 
  in 
  a 
  group 
  at 
  the 
  

   first 
  incision, 
  and 
  sometimes 
  there 
  are 
  many 
  more 
  in 
  each 
  of 
  the 
  groups 
  

   than 
  the 
  numbers 
  given 
  above. 
  I 
  have 
  found 
  two 
  lots 
  on 
  willow 
  in 
  our 
  

   collection 
  where 
  the 
  number 
  and 
  closeness 
  of 
  arrangement 
  of 
  these 
  pores 
  

   suggest 
  A. 
  j 
  u 
  g 
  1 
  a 
  n 
  s 
  - 
  r 
  e 
  g 
  i 
  a 
  e, 
  so 
  that 
  Dr 
  Marlatt, 
  to 
  whom 
  the 
  speci- 
  

   mens 
  were 
  submitted, 
  advances 
  interbreeding 
  as 
  a 
  possible 
  explanation 
  

   of 
  the 
  phenomena. 
  The 
  lobes 
  are 
  three 
  on 
  each 
  side 
  of 
  the 
  median 
  line 
  

   in 
  this 
  willow 
  form, 
  and 
  the 
  ventral 
  glands 
  are 
  more 
  numerous 
  than 
  in 
  

   typical 
  A. 
  ostreaeformis, 
  while 
  the 
  specimens 
  are 
  larger 
  in 
  size. 
  

  

  In 
  the 
  second 
  stage 
  the 
  two 
  pairs 
  of 
  lobes 
  are 
  usually 
  distinctly 
  

   present, 
  though 
  the 
  second 
  are 
  minute. 
  Sometimes 
  a 
  hint 
  of 
  the 
  rudi- 
  

   mentary 
  third 
  ones 
  can 
  be 
  discerned. 
  The 
  incisions 
  are 
  wide 
  and 
  not 
  

  

  