﻿98 
  BRITISH 
  LEPIDOPTERA. 
  

  

  in 
  some 
  instances 
  than 
  in 
  Lymantriid 
  pupa?. 
  The 
  plumes, 
  using 
  the 
  

   term 
  in 
  the 
  broadest 
  sense, 
  fall 
  into 
  two 
  very 
  characteristic 
  groups, 
  

   which 
  we 
  have 
  treated 
  as 
  superfamilies, 
  in 
  order 
  to 
  show 
  that 
  the 
  

   Agdistides 
  equal 
  in 
  biological 
  value 
  the 
  Alucitides, 
  under 
  which 
  title 
  we 
  

   group 
  the 
  rest 
  of 
  the 
  plumes. 
  For 
  our 
  general 
  considerations 
  we 
  have 
  

   discussed 
  the 
  two 
  together 
  in 
  order 
  to 
  contrast 
  their 
  differences 
  and 
  

   compare 
  their 
  resemblances 
  in 
  the 
  various 
  stages. 
  

  

  The 
  pupal 
  and 
  larval 
  features 
  are 
  very 
  important 
  from 
  the 
  point 
  of 
  

   view 
  of 
  grouping 
  the 
  species 
  inter 
  se, 
  and 
  a 
  study 
  of 
  these 
  stages 
  is 
  abso- 
  

   lutely 
  necessary 
  to 
  form 
  a 
  sound 
  basis 
  for 
  the 
  generic 
  divisions, 
  whilst 
  the 
  

   characters 
  found 
  in 
  these 
  stages 
  often 
  separate 
  widely 
  species 
  in 
  which 
  

   the 
  neurational 
  characters 
  are 
  very 
  similar. 
  Thus 
  the 
  Amblyptiliid 
  

   pupa 
  not 
  only 
  shows 
  how 
  distinct 
  is 
  Amblyptilia 
  from 
  Platyptilia, 
  with 
  

   which 
  Meyrick 
  erroneously 
  unites 
  it, 
  but 
  suggests 
  a 
  close 
  alliance 
  with 
  

   Marasmarcha 
  (lunaedactijla), 
  which 
  is 
  usually 
  placed 
  in 
  a 
  quite 
  different 
  

   group, 
  whilst 
  a 
  detailed 
  knowledge 
  of 
  the 
  life-histories 
  must 
  have 
  

   prevented 
  the 
  same 
  author 
  from 
  lumping 
  into 
  the 
  same 
  g^nus, 
  such 
  

   divergent 
  species 
  as 
  Marasmarcha 
  lunaedactyla 
  and 
  Adaina 
  microdactyla, 
  

   which 
  have 
  no 
  point 
  of 
  contact 
  in 
  any 
  stage 
  — 
  egg, 
  larva, 
  pupa 
  or 
  

   imago. 
  The 
  soundest 
  work 
  yet 
  done 
  on 
  the 
  classification 
  of 
  the 
  

   plumes 
  is 
  undoubtedly 
  that 
  of 
  Hofmann 
  ("Die 
  deutschen 
  Ptero- 
  

   phorinen," 
  Berichte 
  des 
  naturwiss'nschaftlichen 
  Vereines 
  zu 
  Regensburg, 
  

   v., 
  1894-1895), 
  with 
  the 
  general 
  arrangement 
  of 
  whose 
  work 
  we 
  are 
  in 
  

   close 
  agreement. 
  His 
  knowledge 
  of 
  the 
  early 
  stages 
  of 
  many 
  species 
  

   has 
  led 
  him 
  to 
  avoid 
  the 
  greater 
  pitfalls 
  into 
  which 
  Meyrick 
  has 
  fallen 
  

   through 
  being 
  unable 
  to 
  check 
  the 
  results 
  obtained 
  from 
  a 
  study 
  of 
  the 
  

   imago 
  by 
  those 
  obtained 
  from 
  study 
  of 
  the 
  larva? 
  and 
  pupa?. 
  Taking 
  

   his 
  two 
  main 
  divisions 
  (op. 
  cit. 
  separ. 
  pp. 
  23 
  et 
  seq.) 
  as 
  our 
  Aydistides 
  

   and 
  Alucitides, 
  and 
  his 
  two 
  chief 
  subdivisions 
  of 
  the 
  latter 
  as 
  our 
  

   Platyptiliidae 
  and 
  Alucitidae, 
  we 
  believe 
  that 
  his 
  genera 
  are 
  well 
  placed, 
  

   yet 
  he 
  has 
  no 
  appreciation 
  of 
  the 
  amazing 
  difference 
  of 
  such 
  larva? 
  and 
  

   pupa? 
  as 
  those 
  of 
  Leioptilus 
  tephradactyla 
  and 
  Adaina 
  microdaetyla, 
  which 
  

   he 
  places 
  in 
  the 
  same 
  genus, 
  nor 
  of 
  the 
  gulf 
  that 
  exists 
  between 
  Porrittia 
  

   yalactodactyla 
  on 
  the 
  one 
  hand, 
  and 
  Alucita 
  pentadactyla 
  on 
  the 
  other, 
  

   or 
  between 
  both 
  these 
  and 
  Wheeleria 
  megadactyla 
  (spilodactyla) 
  and 
  

   Merrifieldia 
  tridaetyla. 
  

  

  It 
  may 
  be 
  well, 
  however, 
  before 
  entering 
  into 
  further 
  detail, 
  to 
  

   consider 
  at 
  length 
  the 
  various 
  stages 
  of 
  the 
  Alucitids, 
  so 
  that 
  the 
  

   general 
  morphology 
  of 
  these 
  insects 
  may 
  be 
  properly 
  appreciated. 
  

  

  The 
  Alucitid 
  egg 
  gives 
  very 
  little 
  clue 
  to 
  the 
  affinities 
  of 
  the 
  super- 
  

   family; 
  it 
  is 
  exceedingly 
  simple 
  and 
  not 
  a 
  highly 
  elaborated 
  egg, 
  and 
  

   might 
  have 
  relationship 
  with 
  those 
  of 
  any 
  of 
  the 
  more 
  generalised 
  

   superfamilies 
  of 
  lepidoptera 
  ; 
  it 
  is, 
  however, 
  very 
  different 
  from 
  the 
  

   imbricated 
  eggs 
  of 
  Tortricids 
  and 
  many 
  Pyralids. 
  The 
  egg 
  is 
  flat, 
  

   roughly 
  oval 
  in 
  outline, 
  one 
  end 
  broader 
  and 
  thinner 
  than 
  the 
  other, 
  

   the 
  narrower 
  and 
  thicker 
  end 
  being 
  squared 
  off, 
  and 
  carrying 
  at 
  its 
  

   somewhat 
  flattened 
  end 
  the 
  micropyle 
  ; 
  the 
  shell 
  is 
  thin 
  and 
  trans- 
  

   parent, 
  the 
  upper 
  surface 
  somewhat 
  flattened 
  or 
  sunken, 
  and 
  practically 
  

   devoid 
  of 
  ribs, 
  pitting, 
  and 
  almost 
  entirely 
  of 
  any 
  structural 
  surface 
  

   modification, 
  there 
  being 
  merely 
  the 
  slightest 
  trace 
  of 
  a 
  polygonal 
  

   reticulation. 
  Chapman 
  notes 
  (Trans. 
  Ent. 
  Soc. 
  Lond., 
  1896, 
  p. 
  145) 
  : 
  

   " 
  The 
  ovum 
  is 
  of 
  oval 
  section 
  in 
  every 
  direction, 
  a 
  form 
  that 
  may 
  most 
  

   easily 
  be 
  described 
  as 
  that 
  of 
  an 
  ordinary 
  bird's 
  egg, 
  if 
  laid 
  on 
  its 
  side 
  

  

  