﻿The 
  British 
  Species 
  of 
  Andrena 
  and 
  Nomada. 
  293 
  

  

  Table 
  of 
  $ 
  Andrena. 
  

  

  A. 
  (B) 
  Very 
  small 
  (at 
  most 
  about 
  7 
  mm. 
  long) 
  black-bodied 
  species, 
  

   with 
  dark 
  hind 
  tibiae 
  ; 
  abdomen 
  with 
  the 
  general 
  surface 
  

   above 
  glabrous, 
  the 
  basal 
  segment 
  in 
  nearly 
  all 
  dull 
  

   from 
  the 
  surface 
  rugulosity, 
  as 
  seen 
  under 
  a 
  strong 
  

   lens 
  ; 
  if 
  it 
  is 
  polished 
  as 
  in 
  nana 
  K. 
  the 
  propodeum 
  has 
  

   dense 
  and 
  (for 
  the 
  size 
  of 
  the 
  insect) 
  strong 
  rugosities 
  

   over 
  the 
  whole 
  of 
  its 
  anterior 
  area. 
  

   (Scopa 
  pale, 
  floccus 
  imperfect, 
  area 
  of 
  i^ropodeum 
  well 
  

   exposed, 
  the 
  hairs 
  around 
  it 
  being 
  sparse.) 
  

  

  1. 
  (2) 
  Basal 
  abdominal 
  segment 
  polished 
  and 
  with 
  a 
  copious 
  

  

  distinct 
  puncturation, 
  the 
  2nd 
  clearly 
  and 
  finely 
  punc- 
  

   tured, 
  the 
  punctures 
  as 
  dense 
  as 
  possible 
  except 
  on 
  the 
  

   apical 
  impression, 
  which 
  has 
  only 
  sparse 
  and 
  shallow 
  

   puncturation 
  nana. 
  

  

  2. 
  (1) 
  Basal 
  segment 
  rugulose, 
  rarely 
  shining, 
  the 
  2nd 
  with 
  very 
  

  

  feeble 
  punctures 
  amidst 
  the 
  rugulosities 
  of 
  the 
  surface 
  

   or 
  without 
  punctures. 
  

  

  3. 
  (4) 
  Nearly 
  the 
  whole 
  flagellum 
  beneath 
  and 
  the 
  apical 
  joint 
  at 
  

  

  least 
  above 
  red; 
  basal 
  abdominal 
  segment 
  distinctly 
  

   shining 
  on 
  the 
  disc, 
  the 
  minute 
  surface 
  sculpture 
  hardly 
  

   visible 
  under 
  a 
  strong 
  lens, 
  except 
  on 
  the 
  apical 
  margin. 
  

  

  namila. 
  

  

  4. 
  (3) 
  If 
  the 
  antennae 
  are 
  coloured 
  as 
  above, 
  there 
  is 
  a 
  dense 
  

  

  surface 
  sculpture 
  on 
  the 
  basal 
  abdominal 
  segment, 
  

   making 
  it 
  quite 
  dull 
  on 
  the 
  disc. 
  

  

  5. 
  (6) 
  A 
  dense 
  snow-white 
  band 
  occupies 
  the 
  whole 
  apical 
  impres- 
  

  

  sion 
  of 
  the 
  4th 
  abdominal 
  segment, 
  concealing 
  the 
  sur- 
  

   face, 
  except 
  that 
  there 
  may 
  be 
  a 
  slight 
  interruption 
  in 
  

  

  the 
  middle 
  spreta. 
  

  

  (Apical 
  impressions 
  of 
  2nd 
  and 
  3rd 
  segments 
  with 
  very 
  

   dense 
  sculpture 
  or 
  minute 
  puncturation, 
  the 
  3rd 
  segment 
  

   with 
  the 
  impression 
  deep; 
  stigma 
  pale 
  yellow.) 
  

  

  6. 
  (5) 
  Apical 
  impression 
  of 
  4th 
  segment 
  not 
  so 
  concealed, 
  the 
  

  

  hairs 
  being 
  so 
  spaced 
  that 
  the 
  surface 
  is 
  visible 
  between 
  

   them, 
  and 
  in 
  some 
  species 
  there 
  is 
  only 
  a 
  scanty 
  fringe. 
  

  

  7. 
  (8) 
  Apical 
  impression 
  of 
  3rd 
  segment 
  deep, 
  this 
  and 
  often 
  that 
  

  

  of 
  the 
  2nd 
  brightly 
  shining 
  or 
  polished 
  in 
  some 
  aspects, 
  

   the 
  surface 
  sculpture 
  being 
  faint 
  or 
  hardly 
  visible. 
  

  

  saundersella. 
  

  

  (Stigma 
  pale 
  in 
  the 
  middle; 
  the 
  anterior 
  area 
  of 
  the 
  

  

  propodeum 
  nearly 
  always 
  with 
  the 
  rugosities 
  failing 
  

  

  posteriorly, 
  where 
  the 
  surface 
  appears 
  merely 
  granulate. 
  ) 
  

  

  