﻿PLATYPTILIA 
  GONODACTYLA. 
  

  

  213 
  

  

  that 
  the 
  habit 
  is 
  more 
  frequent 
  in 
  the 
  early 
  brood 
  than 
  is 
  generally 
  

   supposed 
  in 
  Britain. 
  

  

  Pupa. 
  — 
  The 
  pupa 
  has 
  a 
  short 
  sharp 
  beak. 
  It 
  has 
  the 
  same 
  mark- 
  

   ings, 
  and 
  sometimes 
  the 
  same 
  colour 
  as 
  the 
  larva, 
  but 
  varies 
  much 
  

   from 
  very 
  pale 
  to 
  very 
  dark. 
  The 
  general 
  outline 
  of 
  the 
  pupa 
  is 
  

   characteristic 
  of 
  that 
  of 
  the 
  group. 
  The 
  portion 
  from 
  the 
  metathorax 
  

   to 
  the 
  3rd 
  abdominal 
  segment 
  inclusive 
  is 
  fairly 
  cylindrical 
  (about 
  2mm. 
  

   in 
  diameter), 
  but 
  with 
  a 
  dorsal 
  hollow 
  at 
  the 
  1st 
  abdominal 
  segment 
  

   on 
  each 
  side 
  by 
  way 
  of 
  waist 
  ; 
  in 
  front 
  of 
  this 
  portion, 
  the 
  posterior 
  

   end 
  of 
  dorsal 
  ridges 
  (combined) 
  at 
  posterior 
  angle 
  of 
  mesothorax 
  stands 
  

   up 
  a 
  little, 
  and 
  from 
  this 
  point 
  the 
  dorsal 
  line 
  quickly 
  curves 
  ventrally 
  

   to 
  apex 
  of 
  nosespine. 
  The 
  front 
  of 
  pupa 
  is 
  thus 
  a 
  slope 
  of 
  about 
  30° 
  

   from 
  being 
  directly 
  frontad, 
  consisting 
  of 
  head, 
  pro- 
  and 
  mesothorax. 
  

   The 
  nosespine 
  and 
  eyes 
  form 
  a 
  ventral 
  projection 
  beyond 
  the 
  cylindrical 
  

   mass 
  of 
  the 
  pupa. 
  The 
  free 
  abdominal 
  segments 
  taper 
  at 
  an 
  increasing- 
  

   angle 
  (and 
  are 
  therefore 
  curved), 
  to 
  the 
  cremaster. 
  The 
  pupa 
  is 
  very 
  

   like 
  that 
  of 
  P. 
  isodactylus, 
  it 
  has 
  a 
  similar 
  short 
  nosehorn, 
  with 
  a 
  

   slightly 
  sharper 
  point, 
  and 
  it 
  is 
  also 
  without 
  cremastral 
  extension 
  on 
  

   the 
  9th 
  abdominal 
  segment, 
  i.e., 
  it 
  ranges 
  with 
  that 
  of 
  P. 
  isodactylus 
  in 
  

   this 
  respect, 
  but, 
  as 
  a 
  matter 
  of 
  fact, 
  it 
  is 
  rather 
  better 
  provided, 
  for 
  P. 
  

   isodactylus 
  has 
  two 
  hairs, 
  abortively 
  hooked, 
  and 
  may 
  have 
  one 
  or 
  two 
  

   more 
  or 
  less 
  ; 
  P. 
  gonodactyla 
  has 
  four 
  hairs 
  fairly 
  well 
  hooked, 
  one 
  at 
  

   posterior 
  end 
  of 
  anal 
  scar, 
  another 
  further 
  out 
  opposite 
  front 
  of 
  scar 
  

   (these 
  are 
  really, 
  therefore, 
  on 
  the 
  10th 
  abdominal 
  segment, 
  but 
  they 
  

   belong 
  to 
  the 
  ventral 
  and 
  not 
  the 
  terminal 
  armature), 
  and 
  two 
  on 
  the 
  

   boss 
  of 
  the 
  9th 
  abdominal 
  segment, 
  arranged 
  transversely 
  ; 
  the 
  terminal 
  

   set 
  consists 
  of 
  about 
  24 
  on 
  either 
  side. 
  It 
  differs 
  chiefly 
  from 
  the 
  pupa 
  

   of 
  P. 
  isodactylus 
  in 
  having 
  no 
  trace 
  of 
  the 
  spinous 
  flange 
  along 
  the 
  

   posterior 
  borders 
  of 
  the 
  segments. 
  The 
  transverse 
  ridges 
  are 
  fewer 
  

   on 
  each 
  segment, 
  and 
  are 
  narrower 
  in 
  proportion 
  to 
  the 
  spaces 
  between 
  

   them 
  ; 
  thus, 
  on 
  the 
  5th 
  abdominal, 
  are 
  thirteen, 
  with 
  11-18 
  as 
  the 
  limits, 
  

   according 
  to 
  strictness 
  of 
  counting, 
  and 
  the 
  valleys 
  are 
  about 
  three 
  

   times 
  the 
  width 
  of 
  the 
  ridges; 
  they 
  are 
  quite 
  as 
  well 
  provided 
  with 
  

   branch 
  ridges, 
  in 
  places 
  they 
  might 
  be 
  called 
  angulated 
  or 
  zigzag. 
  

   The 
  fine 
  sculpture 
  of 
  pits 
  and 
  skin-points 
  is 
  much 
  the 
  same 
  in 
  distribu- 
  

   tion 
  as 
  in 
  P. 
  isodactylus. 
  The 
  tubercular 
  hairs 
  are 
  about 
  0*05mm. 
  long 
  ; 
  

   tubercle 
  i 
  has 
  about 
  six 
  ridges 
  in 
  front, 
  and 
  the 
  same 
  behind 
  it, 
  ii 
  is 
  on 
  

   the 
  last 
  ridge, 
  iii 
  is 
  in 
  line 
  with 
  i 
  ; 
  the 
  prespiracular 
  accessory 
  is 
  very 
  

   distinct, 
  and 
  is 
  two 
  ridges 
  before 
  spiracle, 
  and 
  iv 
  two 
  behind 
  v 
  ; 
  vi 
  

   is 
  in 
  an 
  area 
  without 
  ridges, 
  due 
  to 
  the 
  three 
  or 
  four 
  penultimate 
  ones 
  

   being 
  here 
  absent 
  ; 
  it 
  is 
  in 
  the 
  line 
  of 
  the 
  last 
  ridge 
  but 
  one 
  ; 
  three 
  

   hairs 
  represent 
  vii 
  ; 
  there 
  is 
  nothing 
  ventrad 
  to 
  this. 
  The 
  scars 
  of 
  the 
  

   prolegs 
  look 
  like 
  little 
  slits 
  between 
  ridges, 
  and, 
  in 
  a 
  mounted 
  specimen, 
  

   appear 
  to 
  have, 
  beneath 
  the 
  slits, 
  cavities 
  as 
  deep 
  as 
  wide; 
  nothing 
  like 
  

   this 
  is 
  seen 
  in 
  P. 
  isodactylus. 
  The 
  cover 
  of 
  first 
  spiracle 
  is 
  almost 
  

   identical 
  with 
  that 
  of 
  /\ 
  isodactylus. 
  There 
  are 
  two 
  pairs 
  of 
  hairs 
  on 
  

   each 
  side 
  of 
  the 
  meso- 
  and 
  metathorax, 
  probably 
  the 
  two 
  most 
  dorsal 
  of 
  

   those 
  in 
  the 
  larva 
  ; 
  both 
  wings 
  are 
  marked 
  off 
  by 
  a 
  quasi-suture. 
  The 
  

   length 
  of 
  the 
  pupa, 
  fully 
  extended 
  (as 
  just 
  before 
  emergence), 
  is 
  12mm., 
  

   contracted 
  it 
  is 
  about 
  2mm. 
  less. 
  The 
  dorsal 
  flanges 
  are 
  marked 
  in 
  

   front 
  of 
  mesothorax, 
  meet 
  near 
  its 
  posterior 
  border, 
  are 
  not 
  very 
  

   marked 
  across 
  metathorax 
  and 
  the 
  1st 
  abdominal 
  segment, 
  are 
  plainer 
  on 
  

   the 
  2nd, 
  and 
  distinct 
  but 
  low 
  on 
  the 
  3rd, 
  where, 
  as 
  usual, 
  they 
  oease. 
  

  

  