﻿PLATYPTILIIDI. 
  157 
  

  

  Jordan 
  states 
  (Ent. 
  Mo. 
  Mag., 
  xviii., 
  p. 
  74) 
  that 
  the 
  Platyptiliid 
  

   species 
  (sens, 
  rest.) 
  have 
  larvae 
  that 
  are 
  generally 
  internal-feeders 
  in 
  

   composite 
  plants 
  ; 
  according 
  to 
  Walsingham, 
  the 
  larvae 
  of 
  P. 
  

   earduidactylus 
  are 
  gregarious 
  in 
  the 
  heads 
  of 
  thistles 
  (reminding 
  one 
  of 
  

   the 
  feeding-habit 
  of 
  the 
  spring-feeding 
  larvae 
  of 
  P. 
  yonodactyla, 
  although 
  

   those 
  of 
  the 
  latter 
  species 
  live 
  singly), 
  whilst 
  those 
  of 
  P. 
  orthocarpi 
  feed 
  

   on 
  the 
  buds 
  and 
  flowers 
  of 
  Orthocarpus, 
  one 
  of 
  the 
  Scrophulariids. 
  

  

  It 
  is 
  interesting 
  to 
  observe 
  that 
  this 
  group 
  presents 
  larvae 
  that 
  still 
  

   retain 
  a 
  certain 
  remnant 
  of 
  the 
  cocoon-forming 
  habit, 
  e.g., 
  Fredericina 
  

   (calodactyla) 
  , 
  Platyptilia 
  (isodactylus, 
  yonodactyla) 
  ; 
  it 
  appears, 
  however, 
  

   to 
  have 
  been 
  lost 
  in 
  Gillmeria. 
  Here 
  it 
  is 
  probably 
  the 
  remnant 
  of 
  a 
  

   former 
  ancestral 
  habit. 
  On 
  the 
  Alucitid 
  side, 
  in 
  Adaina 
  (microdactyla), 
  

   on 
  the 
  other 
  hand, 
  the 
  puparium 
  is 
  a 
  comparatively 
  recent 
  acquire- 
  

   ment, 
  and 
  may 
  be 
  more 
  properly 
  regarded 
  as 
  not 
  really 
  a 
  cocoon 
  at 
  all, 
  

   but 
  the 
  hybernaculum, 
  used 
  later 
  for 
  pupation. 
  

  

  The 
  pupa 
  of 
  Platyptilia 
  is 
  apparently 
  little 
  specialised. 
  It 
  is 
  

   short 
  and 
  thick, 
  that 
  of 
  the 
  Stenoptiliids 
  being 
  decidedly 
  more 
  long 
  

   and 
  slender, 
  after 
  the 
  style 
  of 
  the 
  Agdistids, 
  smooth 
  and 
  with 
  simple 
  

   setae, 
  and 
  is, 
  as 
  far 
  as 
  regards 
  tubercles, 
  the 
  most 
  primitive 
  of 
  all 
  the 
  

   PlatyptiJiine 
  pupae, 
  indeed, 
  so 
  minute 
  are 
  the 
  primitive 
  setae 
  that 
  they 
  

   can 
  only 
  be 
  discerned 
  with 
  a 
  powerful 
  lens 
  ; 
  the 
  Stenoptiliines 
  are 
  

   somewhat 
  close, 
  and 
  so 
  also 
  is 
  EJucnemidophorus, 
  but 
  the 
  former 
  lead 
  

   on 
  to 
  Marasmarcha 
  and 
  Amblyptilia, 
  and, 
  although 
  not 
  presenting 
  the 
  

   remarkable 
  developments 
  exhibited 
  by 
  the 
  latter, 
  are, 
  however, 
  already 
  

   considerably 
  specialised. 
  

  

  We 
  have 
  already 
  noted 
  the 
  peculiarity 
  of 
  the 
  wing 
  form 
  ; 
  in 
  

   addition 
  we 
  may 
  note 
  that 
  the 
  apex 
  of 
  the 
  forewing 
  is 
  also 
  sometimes 
  

   drawn 
  out 
  so 
  as 
  to 
  be 
  slightly 
  hooked. 
  We 
  have 
  further 
  drawn 
  

   attention 
  to 
  the 
  peculiarly 
  Platyptiliid 
  wing-form 
  exhibited 
  in 
  the 
  

   undivided- 
  wing 
  genera 
  Ochyrotica 
  and 
  Steyanodactyla, 
  and, 
  indeed, 
  

   except 
  for 
  the 
  fissures, 
  there 
  is 
  little 
  difference 
  in 
  the 
  outline 
  of 
  these 
  

   and 
  the 
  strict 
  Platyptiliid 
  species. 
  Little 
  is 
  known 
  of 
  the 
  course 
  of 
  the 
  

   development 
  of 
  the 
  scales 
  on 
  the 
  third 
  plumule 
  of 
  the 
  hindwing. 
  

   They 
  really 
  characterise 
  the 
  whole 
  family, 
  Platyptiliidae, 
  and 
  their 
  

   absence 
  in 
  this 
  group 
  seems 
  rather 
  to 
  be 
  a 
  suggestion 
  of 
  specialisation 
  

   than 
  otherwise; 
  thus 
  Gillmeria 
  (oehrodaetyla) 
  , 
  Buckleria 
  (pallidum), 
  

   Stenoptilia 
  (pterodactyla), 
  etc., 
  appear 
  to 
  have 
  lost 
  them. 
  Chapman 
  

   suggests 
  that, 
  theoretically, 
  in 
  Platyptiliids 
  (including 
  Oxyptilids 
  and 
  

   Stenoptiliids) 
  these 
  black 
  scales 
  exist 
  all 
  along 
  the 
  margin, 
  but 
  are 
  more 
  

   developed 
  at 
  particular 
  points 
  more 
  or 
  less 
  different 
  in 
  each 
  species. 
  

   It 
  is 
  oftentimes, 
  of 
  course, 
  not 
  the 
  same 
  patch 
  developed 
  in 
  all 
  species 
  

   or 
  the 
  same 
  little 
  group. 
  B. 
  pallidum, 
  which 
  has 
  practically 
  lost 
  them 
  

   still 
  occasionally 
  shows 
  traces 
  of 
  them. 
  Chapman 
  has 
  an 
  example 
  

   with 
  traces 
  of 
  them 
  on 
  one 
  side 
  only, 
  and 
  another 
  with 
  traces 
  only 
  on 
  

   the 
  other 
  side. 
  Again, 
  as 
  between 
  the 
  Stenoptiliids 
  and 
  the 
  Platyp- 
  

   tiliids, 
  it 
  is 
  to 
  be 
  noted 
  that 
  the 
  latter 
  have 
  the 
  neuration 
  of 
  the 
  fore- 
  

   wings, 
  as 
  represented 
  by 
  the 
  nervure 
  forming 
  the 
  upper 
  boundary 
  of 
  

   the 
  discoidal 
  cell, 
  more 
  generalised 
  than 
  the 
  former 
  (see 
  Hofmann, 
  Die 
  

   deutsch. 
  Pteroph., 
  pi. 
  ii., 
  fig. 
  1, 
  for 
  Platyptiliid 
  form). 
  It 
  is 
  noticeable 
  

   also 
  that 
  the 
  Platyptiliids, 
  that 
  mine 
  in 
  the 
  larval 
  stage, 
  have 
  traces 
  

   of 
  the 
  more 
  usual 
  wing-markings, 
  a 
  character 
  largely 
  lost 
  in 
  those 
  

   assumed 
  to 
  be 
  of 
  more 
  specialised 
  wing-structure. 
  It 
  may 
  be 
  worthy 
  

   of 
  remark 
  here 
  that, 
  in 
  all 
  these 
  considerations, 
  one 
  has 
  to 
  calculate 
  

   on 
  cross-characters, 
  i.e., 
  specialisations 
  in 
  certain 
  directions 
  and 
  not 
  in 
  

  

  