﻿GENERAL 
  BIOLOGICAL 
  CHARACTERS 
  OF 
  THE 
  ALUCITIDES. 
  101 
  

  

  however, 
  without 
  marked 
  exceptions, 
  for 
  Wheeleria 
  megadactyla 
  (spilo- 
  

   dactyla) 
  has 
  a 
  chitinous 
  cone 
  whose 
  base 
  is 
  nearly 
  three 
  times 
  the 
  

   width 
  of 
  the 
  actual 
  spiracle 
  at 
  top, 
  and 
  it 
  stands 
  up 
  from 
  the 
  surface 
  

   to 
  a 
  height 
  quite 
  equal 
  to 
  twice 
  the 
  diameter 
  of 
  the 
  spiracular 
  opening. 
  

   In 
  Leioptilus 
  tephradactyla 
  the 
  height 
  is 
  greater, 
  though 
  the 
  width 
  of 
  

   the 
  base 
  of 
  the 
  cone 
  is 
  proportionally 
  less, 
  despite 
  the 
  fact 
  that 
  it 
  

   stands 
  on 
  a 
  rather 
  large 
  chitinous 
  plate. 
  In 
  Ovendenia 
  septodactyla 
  

   (lienifjianm) 
  the 
  construction 
  is 
  very 
  similar. 
  In 
  Alucita 
  pentad 
  'actyla 
  

   the 
  opening 
  of 
  the 
  spiracle 
  is 
  very 
  large, 
  but 
  it 
  is 
  rather 
  less 
  raised. 
  

   In 
  Merrifieldia 
  tridactyla 
  (tetrad 
  actyla) 
  the 
  cone 
  is 
  short 
  and 
  narrow. 
  

   In 
  Porrittia 
  yalactodactyla 
  it 
  is 
  very 
  similar, 
  but 
  rather 
  higher. 
  In 
  

   Oidaematophorus 
  lithodactyla 
  the 
  spiracle 
  is 
  not 
  unlike 
  that 
  of 
  Adkinia 
  

   zophodactylus, 
  but 
  the 
  base 
  is 
  very 
  transparent 
  and 
  colourless. 
  In 
  

   A. 
  zophodactylus 
  the 
  raised 
  base 
  is 
  hemispherical 
  rather 
  than 
  conical, 
  

   with 
  the 
  darker 
  spiracle 
  on 
  top, 
  hardly 
  more 
  in 
  width 
  than 
  one-third 
  

   the 
  diameter 
  of 
  the 
  hemisphere 
  ; 
  this 
  is 
  most 
  marked 
  in 
  the 
  thoracic 
  

   spiracle. 
  In 
  Stenoptilia 
  pterodactyla 
  the 
  cone 
  is 
  only 
  about 
  twice 
  the 
  

   width 
  of 
  the 
  spiracle 
  ; 
  in 
  Marasmarcha 
  lunaedaetyla 
  (phaeod 
  actyla) 
  the 
  

   cone 
  is 
  wide 
  and 
  not 
  so 
  steep, 
  approaching 
  that 
  of 
  Adkinia 
  zophodactylus, 
  

   whilst 
  that 
  of 
  A. 
  bijnmctid 
  actyla 
  is 
  very 
  similar 
  to 
  that 
  of 
  Stenoptilia 
  

   pterodactyla. 
  Amblyptilia 
  cosmodactyla 
  (acanthod 
  actyla) 
  has 
  rather 
  a 
  

   wide 
  lumen, 
  and 
  a 
  narrow 
  but 
  fairly 
  high 
  cone 
  ; 
  Eucnemidophorus 
  

   rhododactyla 
  has 
  also 
  a 
  wide 
  opening 
  and 
  narrow 
  cone. 
  In 
  C'apperia 
  

   heterod 
  actyla, 
  the 
  spiracle 
  is 
  on 
  a 
  rather 
  sharp, 
  narrow 
  cone, 
  usually 
  

   dark 
  in 
  colour. 
  In 
  the 
  Platyptiliids 
  (sens, 
  strict.) 
  the 
  cone 
  is 
  narrow 
  

   but 
  tall 
  for 
  its 
  width. 
  In 
  Emmelina 
  monodactyla, 
  strangely 
  enough, 
  

   the 
  spiracle 
  is 
  very 
  similar 
  to 
  that 
  of 
  Platyptilia 
  (yonodactyla 
  and 
  

   isodactyla). 
  In 
  Adactylus 
  bennetii 
  the 
  spiracles 
  are 
  characteristic, 
  the 
  

   conical 
  base 
  being 
  rather 
  dark 
  tinted. 
  The 
  larva 
  of 
  Adaina 
  micro 
  - 
  

   dactyla 
  has 
  very 
  large 
  prothoracic 
  and 
  8th 
  abdominal 
  spiracles 
  on 
  

   high, 
  wide, 
  dark 
  cones, 
  the 
  others 
  smaller 
  and 
  less 
  marked. 
  This 
  

   species 
  illustrates 
  to 
  a 
  remarkable 
  degree 
  how 
  the 
  spiracle 
  may 
  be 
  

   modified 
  in 
  the 
  younger 
  stadia. 
  In 
  the 
  first 
  stadium, 
  i.e., 
  the 
  newly- 
  

   hatched 
  larva, 
  each 
  spiracle 
  is 
  a 
  very 
  large 
  structure 
  nearly 
  half 
  the 
  

   width 
  of 
  the 
  segment 
  in 
  diameter, 
  and 
  standing 
  out 
  from 
  the 
  surface 
  

   for 
  an 
  even 
  greater 
  distance. 
  It 
  has 
  a 
  rather 
  narrow 
  neck, 
  and 
  beyond 
  

   this 
  expands 
  into 
  a 
  large 
  cup-shaped 
  mass 
  with 
  fluted 
  sides 
  and 
  a 
  

   rather 
  flat 
  top. 
  It 
  has 
  something 
  the 
  appearance 
  as 
  if 
  the 
  spiracle, 
  

   as 
  it 
  exists 
  in 
  the 
  adult, 
  was 
  represented 
  by 
  the 
  portion 
  to 
  the 
  top 
  of 
  

   the 
  neck, 
  and 
  the 
  portion 
  beyond 
  was 
  a 
  special 
  development, 
  and 
  

   possibly 
  this 
  is 
  so 
  (Chapman). 
  

  

  The 
  skin 
  of 
  the 
  plume 
  larvae 
  is 
  finely 
  spiculated, 
  and 
  those 
  minute 
  

   skin 
  -points 
  appear, 
  as 
  a 
  rule, 
  to 
  be 
  developed 
  in 
  the 
  second 
  stadium, 
  

   and 
  are 
  usually 
  present 
  in 
  some 
  one 
  or 
  other 
  form 
  of 
  development 
  in 
  

   most 
  of 
  the 
  species. 
  They 
  seem 
  to 
  be 
  universally 
  distributed 
  on 
  the 
  

   larval 
  skin, 
  and 
  are 
  often 
  sufficiently 
  well 
  developed 
  to 
  lead 
  one 
  to 
  

   assume 
  that, 
  with 
  very 
  little 
  stimulation, 
  they 
  would 
  develop 
  into 
  

   hairs, 
  but 
  even 
  in 
  the 
  most 
  highly 
  developed 
  spicules 
  there 
  is 
  no 
  joint, 
  

   the 
  spicule 
  being 
  continuous 
  with 
  the 
  epidermal 
  cell 
  beneath. 
  This 
  

   spiculation 
  is 
  usually 
  absent 
  in 
  the 
  first 
  instar, 
  the 
  newly-hatched 
  

   larva 
  being 
  smooth, 
  although 
  larvae 
  of 
  Mtrri/icldia 
  tndactyla, 
  and 
  

   Adactylus 
  bennetii, 
  etc., 
  have 
  it 
  marked 
  more 
  or 
  less 
  strongly 
  in 
  this 
  

  

  