﻿118 
  

  

  BEITISH 
  LEPIDOPTERA. 
  

  

  DoUBLE-SPINA 
  GKOUP. 
  

  

  Length. 
  Diameter. 
  

  

  Merrifieldia 
  tridactyla 
  (tetradactyla) 
  : 
  ? 
  spinae 
  short, 
  

  

  closely 
  adherent 
  to 
  each 
  other 
  

   Wheeleria 
  niveidactyla 
  (baliodactyla) 
  : 
  ? 
  spinae 
  much 
  

  

  twisted, 
  short, 
  but 
  much 
  thicker 
  than 
  in 
  tetradactyla 
  

   Wheeleria 
  megadactyla 
  (spilodactyla) 
  : 
  ? 
  spinae 
  long 
  

  

  and 
  white 
  in 
  colour, 
  clearly 
  separated 
  from 
  each 
  other 
  

   Alucita 
  pentadactyla 
  : 
  ? 
  spinae 
  long, 
  nearly 
  equal 
  in 
  

  

  length 
  and 
  very 
  closely 
  adherent 
  to 
  each 
  other 
  

   Pselnophorus 
  brachydactyla 
  : 
  [ 
  s 
  has 
  a 
  well-developed 
  

  

  retinaculum.'] 
  ? 
  spinae 
  slender 
  and 
  of 
  equal 
  lengths 
  

   Porrittia 
  galactodactyla 
  : 
  ? 
  spinae 
  shorter 
  than 
  mega- 
  

   dactyla, 
  and 
  much 
  more 
  slender 
  

   Oidjematophoruslithodactyla: 
  [ 
  J 
  spina 
  strongly 
  developed 
  

  

  and 
  long, 
  the 
  retinaculum 
  strong.] 
  ? 
  spinae 
  long, 
  

  

  equal 
  in 
  length, 
  this 
  species 
  has 
  longer 
  spina? 
  than 
  any 
  

  

  other 
  British 
  plume 
  

   Emmelina 
  monodactyla 
  : 
  [ 
  s 
  spina 
  fairly 
  thick, 
  and 
  locking 
  

  

  into 
  a 
  strong 
  cluster 
  of 
  scales 
  on 
  the 
  median 
  nervure.] 
  

   ? 
  spinae 
  strongly 
  developed 
  

   Leioptilus 
  tephradactyla 
  : 
  ? 
  spinae 
  much 
  twisted, 
  not 
  

  

  so 
  slender 
  as 
  in 
  septodactyla 
  (leinigianus) 
  

   Ovendenia 
  septodactyla 
  (leinigianus) 
  : 
  ? 
  spinae 
  slender, 
  

  

  closely 
  adhering 
  together. 
  . 
  

   Hellinsia 
  osteodactyla 
  : 
  ? 
  spmae 
  of 
  equal 
  length, 
  shorter 
  

  

  and 
  more 
  slender 
  than 
  those 
  of 
  tephradactyla 
  

   Adaina 
  microdactyla 
  : 
  ? 
  spinae 
  slender 
  and 
  most 
  closely 
  

  

  adherent 
  to 
  each 
  other, 
  the 
  two 
  members 
  being 
  of 
  equal 
  

  

  length 
  and 
  impossible 
  to 
  separate 
  under 
  a 
  low 
  power. 
  

  

  With 
  C 
  objective 
  and 
  application 
  of 
  pressure 
  on 
  the 
  

  

  cover-glass 
  they 
  may 
  be 
  discriminated 
  

   Adaina 
  scarodactyla 
  : 
  [ 
  s 
  spina 
  deeply 
  grooved, 
  bright 
  

  

  brown 
  in 
  colour, 
  retinaculum 
  well-developed 
  as 
  two 
  

  

  separate 
  rings 
  on 
  costal 
  nervure.] 
  ? 
  spinae 
  bent 
  in 
  

  

  contour, 
  but 
  the 
  points 
  closely 
  adherent, 
  pressure 
  of 
  

  

  the 
  cover-glass 
  of 
  slide 
  was 
  needed 
  to 
  separate 
  them 
  ; 
  

  

  they 
  are 
  very 
  slender, 
  short, 
  but 
  of 
  equal 
  length 
  

  

  A 
  

  

  A 
  

  

  tV 
  

  

  A 
  

   A 
  

  

  30 
  

   A 
  

  

  A 
  

   A 
  

  

  ¥§B" 
  

  

  FFO" 
  

   56^6 
  

  

  sis 
  

  

  680 
  

  

  6T0 
  

  

  oV 
  

  

  rib? 
  

  

  This 
  is 
  a 
  marvellous 
  result, 
  because 
  it 
  gives 
  us 
  a 
  dichotomous 
  

   division 
  of 
  the 
  superfamily 
  agreeing 
  with 
  our 
  Platyptiliinae 
  and 
  

   Alucitinae, 
  the 
  Agdistids 
  in 
  this 
  respect 
  suggesting 
  a 
  branch 
  of 
  the 
  

   former. 
  

  

  Meyrick 
  states 
  (Trans. 
  Ent. 
  Soc. 
  Lond., 
  1886, 
  pp. 
  5-6) 
  that 
  

   " 
  The 
  structure 
  of 
  the 
  antennas 
  is 
  practically 
  almost 
  identical 
  through- 
  

   out 
  the 
  family." 
  A 
  suggestive 
  note, 
  however, 
  by 
  Chapman 
  (Proe. 
  Sth. 
  

   Lond. 
  Ent. 
  Soc, 
  1899, 
  p. 
  15) 
  tends 
  to 
  show 
  that 
  this 
  is 
  not 
  altogether 
  

   so. 
  He 
  writes 
  : 
  " 
  The 
  Pterophorids, 
  in 
  a 
  few 
  cases, 
  e.g., 
  Alucita 
  penta- 
  

   dactyla 
  and 
  Marasmarcha 
  phaeodactyla, 
  have 
  antennal 
  hairs 
  between 
  the 
  

   scales 
  dorsally, 
  as 
  inPlutellids, 
  etc. 
  In 
  the 
  majority 
  of 
  species 
  examined, 
  

   however, 
  the 
  hairs 
  are 
  dwindled 
  and 
  out 
  of 
  sight, 
  or 
  absent, 
  so 
  that 
  the 
  

   form 
  is 
  practically 
  that 
  of 
  Obtectse. 
  The 
  presence 
  of 
  the 
  lower 
  forms, 
  

   however, 
  adds 
  to 
  the 
  improbability, 
  already 
  very 
  great, 
  that 
  the 
  Alucitids 
  

   arise 
  from 
  any 
  Pyralid, 
  or 
  other, 
  form 
  with 
  obtect 
  antennas. 
  The 
  form 
  

   inv4. 
  pentadactyla 
  is 
  a 
  very 
  unlikely 
  one 
  to 
  be 
  reached 
  by 
  further 
  evolution, 
  

   and 
  is 
  almost 
  certainly 
  ancestral 
  from 
  more 
  generalised 
  predecessors." 
  

  

  Meyrick 
  has 
  also 
  stated 
  (Trans. 
  Ent. 
  Soc. 
  Lond., 
  1886, 
  pp. 
  5-6) 
  

   that, 
  in 
  this 
  superfamily, 
  " 
  the 
  neuration 
  presents 
  the 
  best 
  characters 
  

   for 
  generic 
  definition." 
  This 
  would 
  probably 
  be 
  true 
  if 
  the 
  characters 
  

  

  