﻿108 
  BRITISH 
  LEPIDOPTERA. 
  

  

  pupa 
  was 
  so 
  interfered 
  with 
  that 
  it 
  did 
  not 
  secure 
  a 
  grip 
  with 
  the 
  

   hooks 
  of 
  the 
  10th 
  abdominal, 
  and 
  then 
  got 
  the 
  hooks 
  under 
  the 
  8th 
  

   from 
  their 
  pocket 
  ; 
  the 
  pupa, 
  nevertheless, 
  did 
  not 
  fall, 
  but 
  was 
  sus- 
  

   tained 
  by 
  the 
  adhesion 
  of 
  the 
  thoracic 
  larval 
  skin 
  to 
  the 
  front 
  of 
  the 
  

   5th 
  and 
  6th 
  abdominal 
  segments, 
  and 
  was 
  so 
  sustained 
  for 
  a 
  consider- 
  

   able 
  time 
  till 
  the 
  pupa 
  reached 
  the 
  silk. 
  It 
  did 
  not, 
  however, 
  do 
  so 
  

   very 
  satisfactorily, 
  and 
  the 
  hooks 
  of 
  the 
  8th 
  segment 
  failed 
  to 
  get 
  a 
  

   proper 
  hold. 
  Tt 
  would 
  seem 
  that 
  the 
  proper 
  use 
  of 
  this 
  adhesion 
  is 
  to 
  

   increase 
  the 
  pressure 
  of 
  the 
  hooks 
  of 
  the 
  8th 
  abdominal 
  against 
  

   the 
  margin 
  of 
  the 
  pocket, 
  and, 
  after 
  the 
  terminal 
  hooks 
  are 
  engaged 
  in 
  

   the 
  silk, 
  to 
  steady 
  the 
  pupa, 
  whilst 
  those 
  of 
  the 
  8th 
  segment 
  are 
  freed 
  

   from 
  the 
  larva-skin 
  and 
  fixed 
  on 
  the 
  silken 
  carpet." 
  We 
  may 
  here 
  

   add 
  that, 
  different 
  as 
  are 
  the 
  Agdistid 
  larvae 
  from 
  those 
  of 
  other 
  

   Alucitids, 
  the 
  pupae 
  are 
  suspended 
  in 
  the 
  same 
  manner 
  as 
  those 
  of 
  all 
  

   other 
  Alucitids, 
  i.e., 
  by 
  the 
  two 
  cremastral 
  groups, 
  one 
  of 
  which 
  is 
  

   terminal, 
  the 
  other 
  under 
  the 
  8th 
  abdominal 
  segment. 
  It 
  is 
  true 
  the 
  

   real 
  place 
  under 
  8 
  is 
  difficult 
  to 
  make 
  out, 
  but 
  seems 
  to 
  be 
  the 
  same 
  

   in 
  all. 
  

  

  The 
  plume 
  pupa 
  is 
  remarkable 
  for 
  its 
  slenderness, 
  the 
  great 
  length 
  

   of 
  the 
  second 
  and 
  third 
  pairs 
  of 
  legs, 
  which 
  are 
  quite 
  free 
  from 
  the 
  

   abdominal 
  segments, 
  and 
  which 
  stand 
  out, 
  when 
  it 
  throws 
  back 
  the 
  

   head 
  and 
  thoracic 
  segments 
  till 
  the 
  head 
  is 
  directed 
  backwards, 
  as 
  it 
  

   does 
  when 
  disturbed. 
  Its 
  general 
  characters 
  are 
  very 
  constant 
  through- 
  

   out 
  the 
  group, 
  and 
  are 
  quite 
  sui 
  generis, 
  so 
  that 
  there 
  can 
  be 
  no 
  doubt 
  

   as 
  to 
  an 
  Agdistid 
  or 
  Alucitid 
  pupa 
  when 
  one 
  has 
  once 
  observed 
  its 
  

   peculiarities. 
  It 
  is 
  highly 
  specialised, 
  yet 
  retains 
  several 
  of 
  the 
  most 
  

   definite 
  characters 
  of 
  the 
  more 
  primitive 
  form 
  of 
  "the 
  pupa-incompleta," 
  

   e.g., 
  the 
  $ 
  pupa 
  has 
  four 
  (4-7) 
  free 
  abdominal 
  segments, 
  and 
  the 
  $ 
  

   three 
  (4-6), 
  t 
  yet 
  it 
  is 
  so 
  attached 
  as 
  to 
  be 
  incapable 
  of 
  progression, 
  

   being 
  fixed 
  by 
  a 
  cremaster 
  that 
  is 
  developed 
  on 
  the 
  8th 
  and 
  10th 
  

   abdominal 
  segments, 
  the 
  only 
  other 
  pupae 
  so 
  far 
  described, 
  attached 
  in 
  

   this 
  manner, 
  being 
  Hypercallia 
  and 
  Anchinia, 
  which, 
  however, 
  are 
  

   obtect 
  pupae 
  of 
  comparatively 
  high 
  type, 
  and 
  in 
  no 
  way 
  related 
  to 
  the 
  

   Alucitids. 
  The 
  Alucitid 
  pupa 
  has 
  scarcely 
  any 
  capacity 
  for 
  lateral 
  

   movement, 
  yet 
  it 
  can 
  bend 
  itself 
  completely 
  over, 
  so 
  that 
  the 
  head 
  

   points 
  directly 
  backwards. 
  

  

  As 
  to 
  the 
  actual 
  structure 
  of 
  the 
  pupa, 
  it 
  is 
  to 
  be 
  noted 
  that 
  it 
  has 
  

   a 
  wide 
  prothorax, 
  no 
  maxillary 
  palpus, 
  the 
  antennae 
  and 
  maxillae 
  adhere 
  

   to 
  the 
  small 
  frontal 
  headpiece, 
  separating 
  from 
  the 
  other 
  parts 
  on 
  

   dehiscence, 
  the 
  eyecovers 
  going 
  with 
  the 
  dorsal 
  headpiece. 
  The 
  pupa 
  

  

  * 
  Chapman 
  adds 
  (loc. 
  cit., 
  p. 
  85): 
  "In 
  Hypercallia 
  and 
  Anchinia 
  the 
  method 
  

   of 
  pupal 
  suspension 
  is 
  precisely 
  the 
  same 
  as 
  in 
  the 
  Alucitids 
  (Pterophorids), 
  and, 
  in 
  

   these, 
  the 
  anal 
  hooks 
  are 
  supplemented 
  by 
  some 
  on 
  the 
  ventral 
  aspect 
  of 
  the 
  8th 
  

   abdominal 
  segment 
  in 
  like 
  manner. 
  There 
  can 
  be 
  little 
  doubt 
  that 
  their 
  use 
  is 
  the 
  

   same 
  as 
  in 
  the 
  Pterophorids, 
  both 
  to 
  secure 
  safety 
  at 
  the 
  time 
  of 
  moult 
  and 
  stiffness 
  

   in 
  the 
  pupal 
  position 
  afterwards. 
  Are 
  these 
  instances 
  of 
  the 
  separate 
  origin 
  of 
  

   complex 
  apparatus 
  and 
  functions, 
  in 
  unrelated 
  species, 
  or 
  is 
  there 
  any 
  possible 
  rela- 
  

   tionship 
  ? 
  The 
  pupae 
  are 
  certainly 
  otherwise 
  so 
  very 
  different 
  that 
  such 
  relationship 
  

   must 
  be 
  distant." 
  

  

  f 
  Chapman 
  observes 
  that 
  the 
  number 
  of 
  free 
  segments 
  of 
  the 
  pupa, 
  being 
  

   four 
  in 
  the 
  J 
  and 
  three 
  in 
  the 
  ? 
  , 
  agrees 
  with 
  that 
  in 
  the 
  Tor 
  trices. 
  This, 
  how- 
  

   ever, 
  is 
  not 
  to 
  be 
  considered 
  as 
  evidence 
  of 
  near 
  relationship, 
  but 
  only 
  as 
  implying 
  

   that 
  both 
  have 
  reached 
  the 
  same 
  stage 
  of 
  pupal 
  evolution, 
  still 
  it 
  leaves 
  it 
  quite 
  

   possible 
  that 
  such 
  relationship 
  does 
  exist. 
  

  

  