﻿344 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  on 
  the 
  spine 
  of 
  one 
  surface, 
  a 
  spine 
  of 
  the 
  other 
  surface 
  may 
  usually 
  be 
  

   detected 
  close 
  by, 
  though 
  somewhat 
  out 
  of 
  focus 
  (pi. 
  ii, 
  fig. 
  i 
  b^b). 
  

   This 
  fact 
  will 
  be 
  taken 
  for 
  granted 
  in 
  the 
  following 
  description, 
  and 
  no 
  

   farther 
  mention 
  of 
  it 
  will 
  be 
  made. 
  

  

  The 
  plates, 
  which 
  are 
  called 
  also 
  gland 
  hairs, 
  or, 
  by 
  Green, 
  squames, 
  

   extend, 
  in 
  general, 
  nearly 
  parallel 
  to 
  the 
  main 
  axis 
  of 
  the 
  body, 
  and 
  

   appear 
  soft 
  and 
  for 
  the 
  most 
  part 
  clearer 
  and 
  broader 
  than 
  the 
  spines, 
  

   and 
  lack 
  the 
  bulbous 
  base, 
  but 
  they 
  assume 
  various 
  forms 
  and 
  may 
  be 
  

   either 
  simple 
  and 
  hair-like, 
  or 
  forked 
  or 
  fringed 
  at 
  the 
  tip. 
  Varying 
  out- 
  

   lines 
  are 
  shown 
  in 
  figure 
  i 
  at 
  c, 
  c, 
  c, 
  c. 
  They 
  are 
  often 
  hard 
  to 
  detect 
  

   definitely, 
  as 
  they 
  are 
  transparent 
  and 
  sometimes 
  disappear 
  in 
  clearing, 
  

   either 
  through 
  actual 
  dissolution 
  or 
  by 
  attaining 
  the 
  same 
  refractive 
  index 
  

   as 
  the 
  mounting 
  medium. 
  Their 
  function 
  is 
  probably 
  connected 
  with 
  the 
  

   excretion 
  of 
  the 
  scale. 
  

  

  The 
  margin 
  is 
  often 
  cut 
  in 
  or 
  incised. 
  In 
  the 
  following 
  species 
  two 
  

   pairs 
  of 
  incisions 
  can 
  usually 
  be 
  detected, 
  the 
  second 
  being 
  comparatively 
  

   inconspicuous 
  (pi. 
  ii, 
  fig. 
  i 
  d, 
  d). 
  

  

  Beside 
  the 
  incisions 
  are 
  heavily 
  chitinized 
  places 
  which 
  appear 
  dark 
  

   in 
  the 
  cleared 
  specimens. 
  These 
  have 
  been 
  spoken 
  of 
  by 
  Prof. 
  Corn- 
  

   stock 
  as 
  the 
  " 
  thickened 
  margin 
  of 
  the 
  incisions," 
  but 
  by 
  later 
  writers 
  

   are 
  more 
  frequently 
  termed 
  " 
  chitinous 
  processes 
  " 
  ; 
  and 
  this 
  phrase 
  I 
  shall 
  

   use, 
  applying 
  it 
  also 
  to 
  the 
  thickenings 
  which 
  sometimes 
  appear 
  on 
  the 
  

   inner 
  margins 
  of 
  the 
  median 
  lobes. 
  These 
  last 
  have 
  been 
  spoken 
  of 
  as 
  

   " 
  club-shaped 
  processes 
  " 
  ; 
  but, 
  ag 
  this 
  term 
  has 
  also 
  been 
  applied 
  to 
  

   other 
  organs, 
  it 
  seems 
  wiser 
  to 
  discard 
  it, 
  simply 
  giving 
  definiteness 
  to 
  

   the 
  term 
  '' 
  chitinous 
  processes 
  " 
  by 
  some 
  phrase 
  of 
  location. 
  Different 
  

   forms 
  of 
  these 
  processes 
  are 
  shown 
  in 
  plate 
  ii, 
  figure 
  i 
  e, 
  e, 
  e, 
  e. 
  A 
  gen- 
  

   eral 
  thickening 
  of 
  the 
  body 
  wall 
  inward 
  from 
  the 
  lobes 
  frequently 
  occurs, 
  

   but 
  is 
  usually 
  rather 
  indefinite 
  in 
  appearance 
  (fig. 
  if). 
  

  

  As 
  the 
  insect 
  is 
  so 
  much 
  flattened, 
  there 
  are 
  practically 
  but 
  two 
  aspects, 
  

   the 
  dorsal 
  and 
  the 
  ventral. 
  In 
  a 
  well 
  cleared 
  specimen 
  the 
  organs 
  of 
  both 
  

   sides 
  are 
  visible 
  at 
  once, 
  yet 
  by 
  careful 
  focusing 
  can 
  be 
  distinguished. 
  

   In 
  plate 
  ii, 
  figure 
  i, 
  the 
  superficial 
  organs 
  of 
  the 
  ventral 
  side 
  are 
  

   represented 
  in 
  the 
  left 
  half 
  of 
  the 
  figure 
  ; 
  those 
  of 
  the 
  dorsal 
  side 
  on 
  the 
  

   right- 
  Perhaps 
  the 
  most 
  important 
  of 
  these 
  superficial 
  organs 
  are 
  those 
  

   which 
  appear 
  on 
  the 
  ventral 
  side 
  of 
  the 
  body 
  as 
  groups 
  of 
  distinct 
  circu- 
  

   lar 
  organs 
  with 
  several 
  tiny 
  perforations 
  in 
  the 
  middle 
  of 
  each. 
  They 
  

   are 
  the 
  openings 
  of 
  glands 
  which 
  presumably 
  secrete 
  the 
  covering 
  of 
  the 
  

   eggs, 
  and 
  have 
  been 
  variously 
  named 
  the 
  spinnerets, 
  the 
  paragenital 
  

   glands, 
  the 
  circumgenital 
  glands 
  and 
  the 
  ventral 
  grouped 
  glands. 
  I 
  shall 
  

  

  