﻿282 
  Mr. 
  R. 
  C. 
  L. 
  Perkins 
  on 
  

  

  process 
  much 
  like 
  that 
  of 
  vaga. 
  The 
  intermediate 
  ventral 
  

   segments 
  with 
  special 
  ciliation, 
  excessively 
  dense 
  on 
  the 
  5th. 
  

  

  Both 
  sexes 
  with 
  the 
  abdominal 
  surface 
  shining 
  between 
  

   the 
  distinct 
  punctures, 
  the 
  apical 
  impressions 
  of 
  the 
  2nd 
  

   and 
  3rd 
  densely 
  and 
  distinctly 
  punctured, 
  a 
  distinct 
  

   pattern 
  of 
  narrow 
  and 
  interrupted 
  bands 
  formed 
  by 
  dense 
  

   short 
  white 
  or 
  whitish 
  hairs 
  on 
  the 
  apices 
  of 
  segments 
  2-4. 
  

  

  Scopa 
  of 
  the 
  $ 
  normal, 
  floccus 
  almost 
  perfect, 
  much 
  as 
  

   in 
  vaga 
  or 
  cineraria. 
  

  

  In 
  the 
  following 
  tables 
  the 
  natural 
  sequence 
  of 
  the 
  

   species 
  is 
  not 
  kept 
  in 
  the 
  case 
  of 
  the 
  Andrenas, 
  while 
  the 
  

   species 
  of 
  Nomada, 
  on 
  the 
  other 
  hand, 
  follow 
  in 
  almost 
  

   natural 
  order, 
  excepting 
  N 
  .fabriciana, 
  which 
  might 
  probably 
  

   be 
  best 
  placed 
  next 
  to 
  flavoguitata. 
  

  

  The 
  antennal 
  characters 
  are 
  most 
  easily 
  observed 
  in 
  

   specimens 
  which 
  have 
  these 
  organs 
  more 
  or 
  less 
  at 
  right 
  

   angles 
  to 
  the 
  long 
  axis 
  of 
  the 
  head, 
  and 
  the 
  measurements 
  

   are 
  always 
  to 
  be 
  taken 
  from 
  the 
  front 
  or 
  lower 
  side 
  of 
  the 
  

   joints, 
  the 
  insect 
  being 
  held 
  with 
  its 
  head 
  towards 
  the 
  

   observer. 
  

  

  The 
  floccus 
  is 
  best 
  seen 
  when 
  the 
  specimen 
  is 
  held 
  as 
  

   above, 
  but 
  with 
  the 
  back 
  downwards. 
  Bees 
  that 
  carry 
  a 
  

   load 
  of 
  pollen 
  should 
  be 
  boxed 
  alive 
  and 
  allowed 
  to 
  free 
  

   themselves 
  from 
  this. 
  

  

  A 
  " 
  perfect 
  " 
  floccus 
  is 
  one 
  in 
  which 
  the 
  hairs 
  that 
  spring 
  

   from 
  the 
  basal 
  part 
  of 
  the 
  trochanter 
  are 
  soft, 
  plumose 
  

   and 
  much 
  curved, 
  and 
  differ 
  very 
  little 
  from 
  those 
  on 
  the 
  

   more 
  apical 
  part. 
  If 
  the 
  basal 
  hairs 
  are 
  stiff 
  er 
  or 
  straighter 
  

   and 
  do 
  not 
  adapt 
  themselves 
  to 
  the 
  curve 
  of 
  the 
  others, 
  

   the 
  floccus 
  is 
  imperfect. 
  These 
  differences 
  will 
  be 
  at 
  once 
  

   appreciated 
  if 
  such 
  a 
  species 
  as 
  the 
  common 
  A. 
  trimmerana 
  

   is 
  compared 
  with 
  any 
  member 
  of 
  the 
  group 
  of 
  A. 
  varians. 
  

   In 
  other 
  countries 
  there 
  are 
  species 
  in 
  which 
  there 
  is 
  no 
  

   true 
  floccus 
  at 
  all, 
  but 
  we 
  have 
  no 
  such 
  forms 
  in 
  Britain. 
  

  

  Table 
  of 
  ^ 
  Andrena. 
  

  

  1. 
  (16) 
  Clypeus 
  yellow 
  or 
  white. 
  

  

  2. 
  (3) 
  Second 
  and 
  3rd 
  abdominal 
  segments 
  red, 
  forming 
  a 
  broad 
  

  

  band 
  between 
  the 
  black 
  basal 
  and 
  apical 
  segments 
  ; 
  a 
  

   large 
  white 
  spot 
  on 
  either 
  side 
  of 
  the 
  white 
  clypeus. 
  

  

  cingulata. 
  

  

  3. 
  (2) 
  Second 
  and 
  3rd 
  segments 
  not 
  all 
  red. 
  

  

  4. 
  (5) 
  Clypeus 
  with 
  the 
  anterior 
  angles 
  forming 
  strong 
  prominent 
  

  

  