﻿170 
  BRUCE 
  F. 
  CUMMINGS. 
  

  

  The 
  genus, 
  Colpocephalum, 
  is 
  in 
  the 
  present 
  state 
  of 
  our 
  knowledge, 
  often 
  difficult 
  

   to 
  separate 
  from 
  Menopon. 
  The 
  new 
  species 
  is, 
  however, 
  placed 
  in 
  Menopon, 
  rather 
  

   than 
  in 
  Colpocephalum, 
  on 
  account 
  of 
  the 
  characteristic 
  Menopoid 
  roofing 
  over 
  of 
  

   the 
  ocular 
  emargination. 
  

  

  I 
  have 
  been 
  unable 
  to 
  refer 
  to 
  Carriker's 
  description 
  of 
  C. 
  extraneum 
  but 
  am 
  satisfied 
  

   from 
  Kellogg's 
  references 
  to 
  it 
  that 
  M. 
  robsoni 
  is 
  a 
  different 
  species. 
  To 
  C. 
  sjostedti 
  

   the 
  new 
  species 
  stands 
  very 
  close. 
  Fortunately, 
  the 
  British 
  Museum 
  possesses 
  a 
  

   single 
  female 
  specimen 
  of 
  C. 
  sjostedti 
  identified 
  by 
  Prof. 
  Kellogg, 
  and 
  by 
  the 
  aid 
  of 
  

   this 
  and 
  his 
  figure 
  and 
  description 
  it 
  has 
  been 
  possible 
  to 
  signal 
  the 
  differences. 
  It 
  

   was 
  sometimes 
  difficult 
  to 
  make 
  the 
  figure 
  agree 
  with 
  the 
  description, 
  and 
  the 
  specimen 
  

   of 
  C. 
  sjostedti 
  is 
  unfortunately 
  a 
  poor 
  mount. 
  But 
  according 
  to 
  the 
  figure 
  and 
  the 
  

   specimen 
  the 
  mesonotum 
  of 
  that 
  species 
  runs 
  out 
  straight 
  into 
  a 
  pointed 
  posterior 
  

   angle. 
  In 
  M 
  . 
  robsoni 
  the 
  outline 
  at 
  the 
  sides 
  of 
  the 
  mesonotum 
  is 
  convex. 
  In 
  the 
  

   abdomen, 
  segments 
  2 
  to 
  6 
  in 
  C. 
  sjostedti 
  have 
  many 
  short 
  spines 
  on 
  the 
  lateral 
  margins, 
  

   segments 
  7 
  to 
  the 
  last 
  each 
  having 
  two 
  elongate 
  hairs 
  in 
  the 
  same 
  position. 
  In 
  

   M. 
  robsoni 
  segment 
  2 
  also 
  has 
  two 
  elongate 
  hairs. 
  The 
  pleural 
  plates 
  are 
  quite 
  

   different 
  in 
  form 
  in 
  the 
  two 
  species 
  ; 
  there 
  are 
  no 
  median 
  plates 
  in 
  M. 
  robsoni, 
  and 
  in 
  

   C. 
  sjostedti 
  on 
  the 
  dorsal 
  surface 
  just 
  inside 
  the 
  pleural 
  region 
  of 
  the 
  abdomen 
  on 
  each 
  

   of 
  the 
  segments 
  2, 
  3, 
  4, 
  6 
  and 
  8 
  there 
  is 
  on 
  each 
  side 
  a 
  single 
  elongate 
  bristle 
  which 
  is 
  

   absent 
  in 
  M. 
  robsoni. 
  Another 
  very 
  considerable 
  difference 
  between 
  the 
  two 
  species 
  

   is 
  to 
  be 
  found 
  in 
  the 
  sternites 
  of 
  the 
  thorax, 
  which 
  are 
  different 
  in 
  form 
  (particularly 
  

   the 
  metasternum), 
  and 
  the 
  chaetotaxy 
  is 
  on 
  an 
  entirely 
  different 
  plan. 
  

  

  External 
  Form, 
  Female. 
  — 
  General 
  conformation 
  peculiar. 
  The 
  thorax 
  dorso-ven- 
  

   trally 
  is 
  deep 
  and 
  antero-posteriorly 
  very 
  long. 
  The 
  abdomen 
  is 
  very 
  short 
  and 
  

   decreases 
  rapidly 
  in 
  depth 
  from 
  the 
  base 
  to 
  the 
  apex. 
  Head 
  : 
  The 
  figure 
  gives 
  an 
  

   accurate 
  idea 
  of 
  the 
  shape 
  of 
  the 
  head, 
  and 
  a 
  reference 
  to 
  it 
  (fig. 
  7) 
  and 
  to 
  the 
  figure 
  

   of 
  the 
  antenna 
  (fig. 
  7, 
  b) 
  makes 
  further 
  details 
  superfluous. 
  Thorax 
  : 
  Wings 
  of 
  

   pronotum 
  rectangular. 
  Posterior 
  margin 
  convex 
  on 
  the 
  mesonotum 
  and 
  rounded. 
  

   Prosternite 
  like 
  a 
  bow 
  and 
  arrow, 
  the 
  tip 
  of 
  the 
  arrow 
  pointing 
  to 
  the 
  rear 
  and 
  pro- 
  

   jecting 
  slightly 
  beyond 
  the 
  convex 
  margin 
  of 
  the 
  plate, 
  this 
  margin 
  being 
  semi- 
  

   circular 
  and 
  representing 
  the 
  bow. 
  The 
  anterior 
  part 
  of 
  the 
  prosternite, 
  representing 
  

   the 
  posterior 
  part 
  of 
  the 
  arrow, 
  instead 
  of 
  being 
  narrow 
  is 
  broad. 
  The 
  clavicles 
  run 
  

   down 
  from 
  the 
  anterior 
  shoulders 
  to 
  join 
  the 
  posterior 
  part 
  of 
  the 
  prosternite. 
  The 
  

   mesosternite 
  is 
  a 
  powerful 
  sclerite, 
  densely 
  chitinous 
  and 
  roughly 
  quadrilateral. 
  The 
  

   four 
  angles 
  each 
  with 
  a 
  chitinous 
  ray. 
  The 
  two 
  anterior 
  rays 
  are 
  long, 
  run 
  outwards 
  

   transversely 
  on 
  each 
  side 
  to 
  the 
  lateral 
  margin 
  and, 
  joining 
  the 
  mesonotum, 
  coil 
  

   around 
  the 
  base 
  of 
  the 
  coxa 
  of 
  the 
  second 
  pair 
  of 
  legs 
  so 
  as 
  to 
  form 
  an 
  acebabulun. 
  

   The 
  front 
  margin 
  of 
  the 
  plate 
  is 
  slightly 
  convex. 
  The 
  hind 
  margin 
  is 
  straight. 
  The 
  

   metanotum 
  is 
  produced 
  on 
  each 
  side 
  into 
  two 
  large 
  shoulders. 
  The 
  metasternite 
  is 
  

   the 
  largest 
  of 
  the 
  three 
  sternal 
  plates 
  ; 
  it 
  is 
  dagger-shaped 
  with 
  three 
  acute 
  angles 
  

   anteriorly, 
  one 
  on 
  each 
  side 
  and 
  one 
  in 
  front. 
  Legs 
  : 
  Coxae 
  of 
  first 
  pair 
  lying 
  just 
  

   below 
  the 
  prosternite 
  and 
  in 
  front 
  of 
  the 
  anterior 
  bars 
  of 
  the 
  mesosternite. 
  They 
  are 
  

   nearer 
  to 
  each 
  other 
  than 
  the 
  other 
  two 
  pairs 
  of 
  coxae, 
  and 
  also 
  longer. 
  Abdomen 
  : 
  

   Nine 
  segments, 
  with 
  traces 
  of 
  a 
  tenth 
  on 
  the 
  ventral 
  side 
  at 
  the 
  base. 
  Spiracles 
  

   minute, 
  only 
  5 
  visible. 
  Segments 
  8 
  and 
  9 
  longer 
  than 
  the 
  others. 
  Basal 
  segments 
  

   short, 
  with 
  the 
  suggestion 
  of 
  being 
  somewhat 
  telescoped 
  towards 
  the 
  metathorax. 
  

  

  